US008282728B2

(12) United States Patent (10) Patent No.: US 8,282,728 B2 Subramanian et a]. (45) Date of Patent: Oct. 9, 2012

(54) MATERIALS WITH TRIGONAL 6,541,112 B1 4/2003 Swiler etal. BIPYRAMIDAL COORDINATION AND 6,541,645 B1 * 4/2003 Canary et a1, ~~~~~~~~~~~~~~~~~~~ ~~ 549/5 6,582,814 B2 6/2003 Swiler et al. METHODS OF MAKING THE SAME 7,024,068 B2 * 4/2006 Canary et a1...... 385/15 _ _ 2003/0229131 A1* 12/2003 Sessler et al...... 514/410 (75) Inventors: Mumrpallam A. Subramaman, Philomath, OR (US); Arthur W. Sleight, Philomath, OR (US); Andrew E. Smith, OTHER PUBLICATIONS Rice Lake, W1 (U S) Smith, Andrew E. et al., “Mn3+ in Trigonal Bipyramidal Coordina _ _ tion: A New Blue Chromophore” J. Am. Chem. Soc. vol. 131, No. 47 (73) Assigneei State of Oregon Actllig by and through (available online on Nov. 9, 2009) pp. 17084-17086.* the state Board of Hlgher Edllcatlfm Subramanian, Munirpallam A. et al., “Noval tunable ferroelectric 0“ behalf of Oregon state Unlversltyi compositions: Bal-xLnxTil-xMxO3 (LnILa, Sm, Gd, Dy; MIAl, Corvallis, OR (Us) Fe, Ci)” Solid State Sciences 2 (2000) pp. 507-512.* ( * ) Notice: Subject to any disclaimer, the term of this (COntinued) patent is extended or adjusted under 35 U.S.C. 154(b) by 197 days. _ Primary Examiner * Jess1ca L Ward (21) Appl. No.: 12/802,700 Assistant Examiner * Ross J Christie (74) Attorney, Agent, or Firm * Klarquist Sparkman, LLP (22) Filed: Jun. 10, 2010 (65) Prior Publication Data (57) ABSTRACT Us 2010/0317503 A1 Dec‘ 16’ 2010 Embodiments of compositions comprising materials satisfy _ _ ing the general formula AMl_xM'xM" O3+ are disclosed, Related U's' Apphcatlon Data along With methods of making the maierialys and composi (60) Provisional application No, 61/268,479, ?led on Jun, tions. In some embodiments, M and M' are +3 cations, at least 11, 2009, a portion of the M cations and the M' cations are bound to oxygen in trigonal bipyramidal coordination, and the material (51) Int. Cl. is chromophoric. In some embodiments, the material forms a C043 14/00 (2006.01) crystal structure having a hexagonal unit cell wherein edge a (52) US. Cl...... 106/401; 106/31.13; 501/41; 501/42; has a length of3.50-3.70 A and edge c has a length of 10-13 501/50; 501/53; 501/152 A. In other embodiments, edge a has a length of5.5-7.0 A. In (58) Field of Classi?cation Search ...... 10661.13, particular embodiments, M' is Mn, and Mn is bonded to 106/401; 501/41, 42, 50, 53, 152 oxygen With an apical MniO bond length of 1.80 A to 1.95 See application ?le for complete search history. A In some embodiments, the material is YIn1—xMnxO3s X is greater than 0.0 and less than 0.75, and the material exhibits (56) References Cited a surprisingly intense blue color.

U.S. PATENT DOCUMENTS 6,416,868 B1 7/2002 Sullivan et al. 33 Claims, 8 Drawing Sheets 6,485,557 B1* 11/2002 Swiler ...... 106/479 (7 of 8 Drawing Sheet(s) Filed in Color)

0.00 0,02 0.05 0.1 0.25 0.4 0.5 035 0.9 1,8 US 8,282,728 B2 Page 2

OTHER PUBLICATIONS Shirin et al., “Synthesis and structure of a MnIII(OH) complex gen erated from dioxygen,” Chem. Commun., pp. 1967-1968, 1997. Color Pigments Manufacturers Association, Inc., Classi?cation and Chemical Descriptions of the Complex Inorganic Color Pigments, 4’h Van Aken et al, “Hexagonal YMnO3,” Acta Crystallographica Sec tion C Crystal Structure Communications, pp. 230-232, 2001. ed. (2010).* Fennie et al., “Ferroelectric transition in YMnO3 from ?rst prin Van Aken et al. “Hexagonal YbMnO3 revisited,” Acta Crystal ciples,” Phys. Rev. B., vol. 72, 100103(R), 4 pp. (2005). lographica Section E Structure Reports Online, pp. i87-i89, Sep. 29, Kresse et al., “Ef?cient iterative schemes for ab initio total-energy 2001. calculations using a plane-Wave basis set,” Phys. Rev. B., vol. 54, No. Van Aken et al., “Hexagonal ErMnO3,” Acta Crystallographica Sec 16, pp. 11169-11186 (1996). tion E Structure Reports Online, pp. i38-i40, 2001. Kresse et al., “From ultrasoft pseudopotentials to the projector aug mented-Wave method,” Phys. Rev. B., vol. 59, No. 3, pp. 1758-1775 Van Aken et al., “Hexagonal LuMnO3 revisited,” Acta Crystal (1999). lographica Section E Structure Reports Online pp. i101-i103, Oct. Liechtenstein et al., “Density-functional theory and strong interac 27, 2001. tions: Orbital ordering in Mott-Hubbard insulators,” Phys. Rev. B. Van Aken et al., “Hexagonal ErMnO3,” Acta Crystallographica Sec vol. 52, No. 8, 5 pp. (1995). tion EiElectronic Paper, pp. 7, 2001. Hadermann, “Synthesis and crystal structure of the Sr2Al1_07 Van Aken et al., “Hexagonal YbMnO3 revisited,” Acta Crystal Mn0_93O5 broWnmillerite,” Journal ofMaterials Chemistry, pp. 692 lographica Section EiElectronic paper, 7 pp., 2001. 698, 2007. Van Aken et al., “Hexagonal YMnO3,” Acta Crystallographica Sec “Manganese Blue Hue” Golden Artist Colors, downloaded from tion C, 14 pp., 2001. http://WWW.goldenpaints.com/products/color/heavybody/colors/ 1457infopg.php, 2 pp., May 25, 2010. * cited by examiner US. Patent 0a. 9, 2012 Sheet 1 of8 US 8,282,728 B2

FIG. IA FIG. 13

FIG. 2 FIG. 3 US. Patent 0a. 9, 2012 Sheet 2 of8 US 8,282,728 B2

FIG. 4 US. Patent 0a. 9, 2012 Sheet 3 of8 US 8,282,728 B2

FIG. 5

a’ ((122) "

e’ (dfj, dxy) -¥- 4 e” (dZX! dyz) 4- 4

FIG. 6

US. Patent 0a. 9, 2012 Sheet 5 of8 US 8,282,728 B2

0.00 0.02 0.05 0.1 0.25 0.3 0.4 0.5 0.75 0.9 1.0

FIG. 8 US. Patent 0a. 9, 2012 Sheet 6 of8 US 8,282,728 B2

FIG. 9 US. Patent 0a. 9, 2012 Sheet 7 of8 US 8,282,728 B2

Unit's)Entansity(Am. Q

181528253635484550556’3 28 FIG.10 U S Patent 0a. 9, 2012 Sheet 8 of8 US 8,282,728 B2

mam:mm

FIG. 11

0700a 0 3338 o 0009 w y = 8 x + . 0-6000 R2 : 6.996? 0-5000“ Q Sampie B 94000 n Biue 385 (350Anm) {3.3000

0.2000 y = 0.2142x _ 0.0085 0.1000-— R2 = 0.9928

0.0000 g i ; 000 0.50 ‘L00 1.50 2.00 2.50 bc FIG. 12 US 8,282,728 B2 1 2 MATERIALS WITH TRIGONAL comprises Al, Ga, or In. In particular embodiments, When BIPYRAMIDAL COORDINATION AND y:0, M' is Mn andA isY, Gd, Tb, Dy, Ho, Er, Tm, Yb, or Lu, METHODS OF MAKING THE SAME then M is not Al. In some embodiments, M' is a +3 cation and at least some CROSS REFERENCE TO RELATED of the M'3+ cations are bound to oxygen in a trigonal bipyra APPLICATION midal coordination as M'O5. In certain embodiments, M is a +3 cation, and at least some of the M3+ cations are bound to This application claims the bene?t of the earlier ?ling date oxygen in trigonal bipyramidal coordination as M05. In par ofU.S. Provisional Application No. 61/268,479, ?led Jun. 11, ticular embodiments, M' is Mn, and Mn is bonded to oxygen 2009, Which is incorporated herein by reference in its entirety. With an apical MniO bond length of 1.80 A to 1.95 A. In some embodiments, M' is Mn and the material satis?es ACKNOWLEDGMENT OF GOVERNMENT the general formula AM l_,€Mn,€M"yO3+y. In certain embodi SUPPORT ments, A is Lu, M is Ga, M' is Mn, and the material satis?es the general formula LuGal_xMnxM"yO3+y. In some embodiments, M is Al, M' is Mn, and the material This invention Was made With government support under further includes carbonate. Such materials satisfy the formula DMR08041 67 aWarded by National Science Foundation. The AAl1_xMnxO3_Z,(CO3)Z Where Z is greater than 0.0 and less government has certain rights in the invention. than or equal to 1.0. In some embodiments, M' is Mn, y is 0, and the material FIELD 20 satis?es the general formula AMl_xMnxO3. In certain embodiments, M is In and the material satis?es the formula This invention relates to the synthesis and use of novel YInl_xMnxO3. In particular embodiments, the YIn1_,€Mn,€O3 materials, particularly chromophoric materials, such as mate material has a surprisingly intense blue color. rials useful for coloring paints, inks, including printing inks, In some embodiments, y is 0 and the material satis?es the plastics, glasses, ceramic products and decorative cosmetic 25 formula AM1_xM'xO3. Such materials form crystal structures preparations. having hexagonal layers comprising M05 and M'O5 trigonal bipyramids alternating With layers of A cations. In certain BACKGROUND embodiments, the crystal structure has a unit cell Wherein edge a has a length of3.50-3.70 A and edge c has a length of The development of the ?rst knoWn synthetic blue pig 30 10-13 A. In other embodiments, the crystal structure has a ment, Egyptian blue (CaCuSi4O 10), is believed to have been larger unit cell Wherein edge a has a length of 5.5-7.0 A and patroniZed by the Egyptian pharaohs, Who promoted the edge c has a length of 10-13 A. advancement of pigment technologies for use in the arts. The subsequent quest for blue pigments has a history linked With powerful civiliZations, such as the Han Chinese [Han blue 35 (BaCuSi4O1O)] and the Maya [Maya blue (indigo intercalated in magnesium aluminosilicate clays)]. Currently used blue inorganic pigments include cobalt blue (CoAl2O4), ultrama rine (Na7Al6Si6O24S3), Prussian blue (Fe4[Fe(CN6)]3), and aZurite (Cu3(CO3)2(OH)2). 40 All of these pigments, hoWever, suffer from environmental and/or durability issues. Cobalt is considered to be highly toxic. Ultramarine and aZurite are not stable With respect to In particular, exemplary chromophoric materials include heat and acidic conditions. Additionally, ultramarine manu 45 facture produces a large amount of SO2 emissions. Prussian blue liberates HCN under mild acidic conditions. Hence, there is a need for inorganic pigments, particularly intensely blue inorganic pigments, Which are environmentally benign, earth-abundant and durable. 50

SUMMARY

Embodiments of compositions comprising materials, and embodiments of a method for making the materials, are dis 55 closed. Embodiments of the disclosed material are chro mophoric. Embodiments of the disclosed materials satisfy the general formulaAMl_xM'xM"yO3+y, WhereA is Sc,Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Zn, In, Ga, Ti, Sn, Fe, Mg, or a combination thereof; M is Sc,Y, Gd, Tb, Dy, Ho, Er, Tm,Yb, 60 Lu, Al, Zn, In, Ga, Ti, Sn, Fe, Mg, or a combination thereof, or M is a 1:1 mixture of MA and MB cations Where MA is Zn, Mg, Cu, or a combination thereof, and MB is Ti, Sn, or a combination thereof; M' is Mn, Fe, Al, Ga, In, or a combina tion thereof; M" is Mg, Zn, Cu, or a combination thereof; x is 65 greater than 0.0 but less than or equal to 0.8; y is an integer from 0 to 15. In certain embodiments, at least one of M and M' US 8,282,728 B2 4 7000 C. to about 15000 C. for about 2 hours to about 20 hours to produce the material With the desired color. Embodiments of a method for making the disclosed com positions are disclosed. In some embodiments, the method comprises providing a material that satis?es the formula AMl_xM'xM"yO3+y, and combining the material With at least one additional component to produce the composition. In certain embodiments, the composition is a paint, an ink, a glass, a plastic, a ceramic glaZe, or a cosmetic preparation. In some embodiments, providing the material includes pro viding poWders comprising metals desired in the material, combining the poWders in stoichiometric quantities to achieve a desired ?nal ratio of the metals in the material, and heating the poWders at an effective temperature and for an effective period of time to produce the desired materials. In some embodiments, the poWders Were heated at a tempera ture of from about 7000 C. to about 15000 C. for about 2 hours to about 20 hours to produce the material. The foregoing and other objects, features, and advantages 20 of the invention Will become more apparent from the folloW ing detailed description, Which proceeds With reference to the accompanying ?gures.

Also disclosed herein are compositions including the chro BRIEF DESCRIPTION OF THE DRAWINGS mophoric materials. In some embodiments, the composition 25 includes a chromophoric material according to the formula The patent or application ?le contains at least one draWing AMl_xM'xM"yO3+y, and at least one additional component. In executed in color. Copies of this patent or patent application some embodiments, the composition is a paint or an ink, and publication With color draWing(s) Will be provided by the the additional component is a binder, a solvent, a catalyst, a O?ice upon request and payment of the necessary fee. thickener, a stabilizer, an emulsi?er, a texturiZer, an adhesion 30 FIGS. 1A and 1B are schematic diagrams of the trigonal promoter, a UV stabilizer, a ?attener, a preservative, or each bipyramidal structures of (1A) YMnO3 and (1B) LuGaMgO4 and any combination thereof. In some embodiments, the With Mn or Mg/ Ga shoWn as blue trigonal bipyramids, broWn composition is a colored glass, and the additional component Y or Lu atoms, and turquoise O atoms. FIG. 1B is also is an oxide of silicon, boron, germanium, or a combination consistent With the structure of YbFe2O4 With Fe as blue thereof. In certain embodiments, the chromophoric material 35 trigonal bipyramids, broWnYb atoms, and turquoise O atoms. is YIn1_xMnxO3, and x is greater than 0.0 and less than 0.75. FIGS. 2-5 are schematic diagrams of trigonal bipyramidal In some embodiments, the composition further comprises structures according to the general formula AM1_xM'xO3, at least one additional chromophoric material. In particular With red O atoms, light blue A atoms, and pink M/M' atoms. embodiments, the additional chromophoric material also sat FIGS. 2 and 3 are shoWn from a top perspective, looking doWn is?es the formula AMl_xM'xM"yO3+y. 40 the c-axis. FIGS. 4 and 5 are shoWn from a front perspective, Embodiments of a method for making the disclosed mate With the c-axis being vertical. rials are disclosed. In some embodiments, the method com FIG. 6 is a schematic diagram of the energy levels for Mn prises providing poWders comprising metals desired in the 3d orbitals. material, combining the poWders in stoichiometric quantities FIG. 7 includes graphs of unit cell dimensions and c/a ratio to achieve a desired ?nal ratio of the metals in the material, 45 for the YIn1_xMnxO3 solid solution With values of x from 0.0 and heating the poWders at an effective temperature and for an to 1.0. effective period of time to produce the desired materials. In FIG. 8 is a series of color photographs ofpellets and poW some embodiments, the poWders Were heated at a tempera ders according to several embodiments of the disclosed com ture of from about 700° C. to about 15000 C. for about 2 hours positions. The numbers under the pellets represent the value to about 20 hours to produce the material. In certain embodi 50 of x in the structural formulas YIn1_,€Mn,€O3 and LuGa,C ments, the poWders are metal oxides or metal nitrates. In some Mnl_xMgO4. embodiments, after combining the poWders in stoichiometric FIG. 9 is a series of diffuse re?ectance spectra for the quantities, the poWders are pressed into a pellet before heat YIn1_,€Mn,€O3 solid solution With values of x from 0.05 to 1.0. ing. In particular embodiments, the pellet is ground after FIG. 10 is a series of poWder diffraction patterns from heating to produce a poWder, the poWder is re-pressed into a 55 10-600 20 for the YIn1_,€Mn,€O3 solid solution With values of pellet, and the pellet is heated again at a temperature of from x from 0.0 to 1.0 WithYMnO3 at the bottom andYInO3 at the about 7000 C. to about 15000 C. for about 2 hours to about 20 top. hours. FIG. 11 is a series of full re?ectance curves of materials Also disclosed are embodiments of a method for varying With the formula YIn1_xMnxO3. color in a material having a formula AMl_xM'xM"yO3+y. In 60 FIG. 12 is a graph of absorbance versus be (thickness>< certain embodiments, the material has a color that varies concentration) for materials With the formula YIn1_xMnxO3. along a color continuum as the value of x increases. Thus, the material’ s color can be varied by providing poWders compris DETAILED DESCRIPTION ing metals desired in the material, selecting a value of x to provide a desired color along the color continuum, combining 65 The present disclosure concerns embodiments of materi the poWders in stoichiometric quantities according to the als, particularly chromophoric materials. Certain disclosed value of x, and heating the poWders at a temperature of about embodiments comprise a metal selected from Mn, Fe, Al, Ga, US 8,282,728 B2 5 6 In, or a combination thereof, bound to oxygen in a trigonal and green (a*—negative values indicate green, While positive bipyramidal con?guration. Compositions comprising the values indicate magenta, and its position betWeen yelloW and materials also are disclosed. In particular embodiments, the blue (b*—negative values indicate blue and positive values metal is Mn, and the material has a blue color. Embodiments indicate yelloW). of a method for making the materials also are disclosed. Ferroelectricity is a property of certain nonconducting Manganese is relatively abundant, constituting about crystals that exhibit spontaneous electric polarization, mak 0.085% of the earth’s crust. Among the heavy metals, only ing one side of the crystal positive and the opposite side iron is more abundant. Manganese-containing materials dis negative, that can be reversed in direction by the application playing a variety of colors are knoWn. The observed color of of an external electric ?eld. these compounds is determined by the oxidation state of Gloss is an optical property based on the interaction of light manganese, commonly +II, +III, +IV, +VI and +VII, and the With physical characteristics of a surface; the level of specular associated anions. For example, permanganate (+VII oxida tion state) compounds are purple. Manganese (II) compounds (mirror-like) re?ection of light from a surface. A hexagonal unit cell is one of the seven crystal systems tend to be pink or red in color, although manganese (II) oxide is green. Examples of blue manganese compounds, especially With the general unit cell geometry a:b#c; 0t:[3:90° and bright blue manganese compounds, are less commonly y:l20°. Structures of the compositions disclosed herein are observed. For example, hypomanganate, Mn(V), salts are referred to as hexagonal. Strictly speaking, those With an odd bright blue, but are unstable, and Manganese Blue, Which is a value for y (i.e., l, 3, 5, etc.) are rhombohedral. Rhombohe barium Mn(VI) sulfate is highly toxic. dral unit cells are most frequently described using a hexago The inventors have discovered that a surprisingly intense, 20 nal unit cell, but they can also be described as a cell Where bright-blue color is obtained When Mn3+ is introduced into a:b:c and (XIBIY. For the single layer structure (y:0), both the trigonal bipyramidal sites of metal oxides. the small and large cell structures are true hexagonal unit cells. More information on the rhombohedral-hexagonal I. Terms and De?nitions transformation can be found in textbooks dealing With crys 25 tallography (e.g., “Elements of X-ray Diffraction”, by B. D. The folloWing explanations of terms and abbreviations are Cullity, Addison-Wesley, 1978; pp. 504-505). provided to better describe the present disclosure and to guide Masstone is the undiluted color of a pigment or a pig those of ordinary skill in the art in the practice of the present mented paint, e. g., the color it appears When applied thickly disclosure. As used herein, “comprising” means “including” and no other color is seen beneath it. and the singular forms “a” or “an” or “the” include plural 30 Opacity, or hiding poWer, refers to the ability of a pigment references unless the context clearly dictates otherWise. The to obscure a black design painted on a White background. term “or” refers to a single element of stated alternative ele A pigment is a substance, usually in the form of a dry ments or a combination of tWo or more elements, unless the poWder, that imparts color to another substance or mixture. context clearly indicates otherWise. A solid solution is formed When at least one solid compo Unless explained otherWise, all technical and scienti?c 35 nent is molecularly dispersed Within another solid compo terms used herein have the same meaning as commonly nent, resulting in a homogeneous or substantially homoge understood to one of ordinary skill in the art to Which this neous solid material. A solid solution may be formed, for disclosure belongs. Although methods and materials similar example, by completely or substantially completely dissolv or equivalent to those described herein can be used in the ing tWo solid components in a liquid solvent and then remov practice or testing of the present disclosure, suitable methods 40 ing the liquid solvent to produce the solid solution. and materials are described beloW. The materials, methods, A tint is a color obtained by adding White to a colored and examples are illustrative only and not intended to be limiting. Other features of the disclosure are apparent from pigment. the folloWing detailed description and the claims. Total solar re?ectance (TSR) is a measure of the amount of incident terrestrial solar energy re?ected from a given sur Unless otherWise indicated, all numbers expressing quan 45 face. For example, White coatings exhibit a TSR of 75% or tities of components, molecular Weights, percentages, tem greater, Whereas black coatings may have a total TSR as loW peratures, times, and so forth, as used in the speci?cation or as 3%. claims are to be understood as being modi?ed by the term “about.” Accordingly, unless otherWise indicated, implicitly Trigonal bipyramidal geometry is found When a central atom in a molecule forms bonds to ?ve peripheral atoms at the or explicitly, the numerical parameters set forth are approxi 50 corners of a trigonal dipyramid. Three of the atoms are mations that may depend on the desired properties sought arranged in a planar triangle around the central atom With a and/ or limits of detection under standard test conditions/ methods. When directly and explicitly distinguishing bond angle of 120 degrees betWeen the peripheral atoms; these atoms are called equatorial, or basal, atoms. The embodiments from discussed prior art, the embodiment num remaining tWo atoms are located above and beloW the central bers are not approximates unless the Word “about” is recited. 55 A chromophore is the portion, or moiety, of a molecule that atom, and are called axial, or apical, atoms. There is a bond angle of 90 degrees betWeen the axial and equatorial atoms. is responsible for the molecule’s color. A metal-complex One example of a trigonal bipyramidal molecule is PPS. chromophore is believed to arise from the splitting of d-or bitals When a metal (e.g., a transition metal) binds to ligands. Visible light that hits the chromophores is absorbed by excit 60 ing an electron from its ground state into an excited state. CIE L*a*b* (CIELAB) is a color space (i.e., a model representing colors as an ordered list of three numerical val ues) speci?ed by the International Commission on Illumina tion (Commission Internationale d’Eclairage, CIE). The three 65 coordinates represent the lightness of the color (L*:0:black, FIG. 6 also depicts a trigonal bipyramidal molecule. Some L*:l00:diffuse White), its position betWeen red/magenta crystals have trigonal bipyramidal geometry. In the crystal, US 8,282,728 B2 7 8 the peripheral atoms may be shared by more than one central With reference to Formula 2, A is Y, Sc, Gd, Tb, Dy, Ho, Er, atom as shoWn in FIGS. 1A-1B. Tm,Yb, Lu, or a combination thereof; M is a cation in trigonal bipyramidal coordination, Where M selected from Al, Ga, In, II. Materials With Trigonal Bipyramidal Fe, and combinations thereof; alternatively, M is a 1:1 mix Coordination and Compositions Thereof ture of MA and MB cations Where MA is Zn, Mg, Cu, or a combination thereof, and MB is Ti, Sn, or a combination Embodiments of compositions comprising materials are thereof; M" is Zn, Mg, Cu, or a combination thereof; x is disclosed. In preferred embodiments, the material is chro greater than 0 and less than 1.0; and y is an integer number mophoric. In the disclosed embodiments, the compositions ranging from 0 to 6. include at least one chromophoric material comprising a In other embodiments, the compositions comprise a man metal selected from Mn, Fe, Al, Ga, In, or a combination ganese (III) material according to Formula 3. thereof bound to oxygen in a trigonal bipyramidal con?gura LuGa1iXMnXM"yO3+y Formula 3 tion. In the disclosed embodiments, oxygen atoms occupy all With reference to Formula 4, M" is Zn, Mg, Cu, or a combi ?ve sites coordinated to the central metal in the trigonal nation thereof, x is greater than 0 and less than 1.0, and y is an bipyramid. integer number ranging from 0 to 6. A. Materials In some embodiments, y is 0 and the compositions com A person of ordinary skill in the art Will understand that the prise a manganese (III) material according to Formula 4. following general formulas are compositional formulas and do not necessarily imply chemical structure and/or connec AM 1 iXMnXO3 Formula 4 tivity. As such, the order of individual components in the 20 With reference to Formula 4, x is greater than 0.0 but less than general formulas may be rearranged When Writing speci?c 1.0, andA and M independently are selected fromY, Gd, Tb, formulas to represent embodiments of the disclosed materi Dy, Ho, Er, Tm, Yb, Lu, Al, Ga, In, Zn, Ti, Sn, Fe, Mg, and als. combinations thereof In some embodiments, A and M inde Embodiments of the disclosed compositions comprise a pendently are selected from the group consisting of Y, Al, In, material according to general Formula 1: 25 Ga, and combinations thereof. In certain embodiments Where M is aluminum, the com AM liXM'XM"yO3+y Formula 1 positions further comprise carbonate (CO32_) as shoWn in Formula 5: With reference to Formula 1, A and M independently are selected from Sc, Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga, In, Zn, Ti, Sn, Fe, Mg, or a combination thereof; alternatively, 30 With reference to Formula 5, x is greater than 0.0 but less than M is a 1:1 mixture ofMA and MB cations Where MA is Zn, Mg, 1.0, Z is greater than 0.0 and less than or equal to 1.0; A isY, or Cu, and MB is Ti or Sn; M' is Mn, Fe, Al, Ga, In, or a Gd, Tb, Dy, Ho, Er, Tm,Yb, Lu,Al, Ga, In, Zn, Ti, Sn, Fe, Mg, combination thereof; M" is Mg, Zn, Cu, or a combination and combinations thereof, and M' is Mn, Fe, Ga, In, or a thereof; x is greater than 0.0 but less than 1.0, and y is 0 or a combination thereof. One example is YAlO_6OMnO_4OO3_Z positive integer. In some embodiments, y is an integer from 0 35 (CO3)Z. The presence of carbonate arises from the use of to 15 (i.e., y is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or organic compounds (e.g., citric acid; see Examples 70-76) 15). In particular embodiments, M and M' are cations With a When synthesizing AAlO3. The organic matter decomposes +3 oxidation state, and at least a portion of M and M' cations during synthesis, producing a CO2-rich atmosphere and pro are bound to oxygen in trigonal bipyramidal coordination. moting carbonate formation. In the absence of M' (x:0), In some embodiments, the material is chromophoric. In 40 AAIOZCO3 is produced. As aluminum content decreases, car exemplary embodiments, the material has a color that varies bonate content also decreases and becomes Zero When x:1.0. along a color continuum as the value of x increases. For HoWever, When x is greater than 0.0 and less than 1.0, the example, the material may have a color darkens as the value of carbonate content Z of the compound is variable for any given x increases. value of x. Where C032- replaces O2- in the crystal structure, In some embodiments, at least one of M and M' comprises 45 the adjacent cation loses its trigonal bipyramidal coordina tion, and is thought to assume a distorted octahedral confor a metal selected from Al, Ga, and In. In certain embodiments, mation. Other cations in the crystal structure retain the trigo M is not Al When y is 0, M' is Mn, andA is Sc,Y, Gd, Tb, Dy, nal bipyramidal coordination. Ho, Er, Tm, Yb, Lu. In particular embodiments, the compositions comprise a In some embodiments, A is Sc, Y, Gd, Tb, Dy, Ho, Er, Tm, manganese (III) material according to Formula 6. Yb, Lu, or a combination thereof; M is Al, Ga, In, Fe, or a 50 combination thereof; alternatively M is a 1:1 mixture of Cu YIn1iXMnXO3 Formula 6 and Ti; M' is Mn, Fe, Al, Ga, In, or a combination thereof; M" With reference to Formula 6, x is greater than 0.0 but less than is Mg, Zn, or a combination thereof; x is greater than 0.0 but 1.0. less than or equal to 0.8; and y is 0, 1, or 2. Compositions comprising solid solutions of materials In certain embodiments, M, M', and/ or M" may be a com 55 according to Formulas 1 through 7 are chromophoric. Table 1 bination of the recited elements. For instance, M may be a lists representative Working embodiments of materials mixture of Fe and In, e.g., A(Fe,In)1_xM'xM"yO3+y. One according to Formulas 1 through 7, along With their respec example of such a material isYFeO_ 1 InO_8MnO_ lO3, WhereA is tive colors and crystal structures. Y, M is (FeO_lInO_8), M' is Mn, x is 0.1, and y is 0. Another 60 example is In(InO_2GaO_76)MnO_O4MgO4, Where A is In, M is TABLE 1 (InO_2GaO_76), M' is Mn, M" is Mg, x is 0.04, and y is 1; this composition also can be represented as Composition Color Structure In1.2Ga0.76Nh10o4MgO4 YInO3 White/Lt. YelloW Hexagonal Single layer In some embodiments, the compositions comprise a man YInO_95MnO_O5O3 Sky Blue Hexagonal Single layer ganese (III) material according to Formula 2. 65 YInO_9MnO_1O3 Bright Blue Hexagonal Single layer YInO_85MnO_15O3 Bright Blue Hexagonal Single layer AM 1 iXMnXM' 'yO3+y Formula 2 US 8,282,728 B2

TABLE I-continued TABLE I-continued

Composition Color Structure Composition Color Structure YInO_8MnO_2O3 Bright Blue Hexagonal Single layer YAl0_8OMnO_20O3,Z(CO3)Z Blue/grey Hexagonal Single layer YInO_75MnO_25O3 Royal Blue Hexagonal Single layer 5 LuGaO_99MnO_O1MgO4 Light blue/purple Hexagonal Double layer YInO_7MnO_3O3 Royal Blue Hexagonal Single layer LuGa0_97MnO_03MgO4 Blue/purple Hexagonal Double layer YInO_65MnO_35O3 Navy Blue Hexagonal Single layer LuGaO_95MnO_O5MgO4 Blue/purple Hexagonal Double layer YInO_6MnO_4O3 Navy Blue Hexagonal Single layer LuGaO_9OMnO_1OMgO4 Blue/purple Hexagonal Double layer YInO_55MnO_45O3 Navy Blue Hexagonal Single layer LuGa0_85MnO_l5MgO4 Dark blue/purple Hexagonal Double layer YInO_5MnO_5O3 Dark Navy Blue Hexagonal Single layer LuGaO_97MnO_O3ZnO4 Blue/purple Hexagonal Double layer YInO_25MnO_75O3 Black Hexagonal Single layer 10 LuGaO_95MnO_O5ZnO4 Blue/purple Hexagonal Double layer YInO_1MnO_9O3 Black Hexagonal Single layer ScAlO_99MnO_O1MgO4 Purple Hexagonal Double layer DyIn(,_9Mn(,_1O3 Bright Blue Hexagonal Single layer ScAl0_95Mn0_05MgO4 Purple Hexagonal Double layer DyInO_8MnO_2O3 Royal Blue Hexagonal Single layer ScAlO_9OMnO_95MgO4 Purple Hexagonal Double layer DyInO_7MnO_3O3 Dark Royal Blue Hexagonal Single layer ScAlO_85MnO_15MgO4 Purple Hexagonal Double layer DyInO_6MnO_4O3 Dark Navy Blue Hexagonal Single layer ScAlO_95MnO_O5ZnO4 Blue Hexagonal Double layer DyInO_5MnO_5O3 Dark Navy Hexagonal Single layer 1 5 InGa0_9 7MnO_O3ZnO4 Green Hexagonal Double layer Blue/Black InGaO_97MnO_O3ZnO4 Green Hexagonal Double layer DyInO_4MnO_6O3 Black Hexagonal Single layer InGaO_95MnO_O5ZnO4 Green Hexagonal Double layer DyInO_3MnO_7O3 Black Hexagonal Single layer InGaO_95MnO_O5MgO4 Blue Hexagonal Double layer DyInO_2Mn0_8O3 Black Hexagonal Single layer ScGa0_95MnO_05ZnO4 Blue Hexagonal Double layer HoInO_9MnO_1O3 Bright Blue Hexagonal Single layer ScGaO_95MnO_O5MgO4 Blue Hexagonal Double layer HoInO_8MnO_2O3 Royal Blue Hexagonal Single layer LuGaO_99MnO_O1ZnO4 Blue Hexagonal Double layer HoInO_7MnO_3O3 Dark Royal Blue Hexagonal Single layer 20 LuGaO_95MnO_O5ZnO4 Blue Hexagonal Double layer HoInO_5MnO_5O3 Dark Navy Hexagonal Single layer IH(IHO_2G3-O.8) Blue Hexagonal Double layer Blue/Black O_95MnO_O5MgO4 I HoInO_3MnO_7O3 Black Hexagonal Single layer LHGaOBQMHQOIZHZOS B1116 H?xagonal Trlpl? layer HoInO_2MnO_8O3 Black Hexagonal Single layer LuGaoosMnooszlbos B1116 H?xagonal Tnpl6 layer HoInO_lMn0_9O3 Black Hexagonal Single layer In(Ino.2Gao.s) B1116 H?xagonal Doubl? lay6r ErInO_9MnO_1O3 Flat Royal Blue Hexagonal Single layer 25 0.95Mn0.05MgO4 ErInO_8MnO_2O3 Royal Blue Hexagonal Single layer ErInO_5MnO_5O3 Dark Navy Blue Hexagonal Single layer ______Emmy/[H0803 Black Hgxagonal singlg laygr Materials according to Formula 6 exhibit a surprisingly YCuO_5TiO_5O3 Yellow-green Hexagonal Single layer intense and bright blue color despite the fact thatYInO3 (XIO) YAlo-lcuo-45Tl9-45o3 Bright grew Hexagonal Single layer andYMnO3 (XII) are White and black, respectively. Indeed, a YGaO_1CuO_45Ti0_45O3 Bright green Hexagonal Single layer 30 , YInO_lCuO_45TiO_45O3 Bright grew H?xagonal singl? lay?r blue color '15 observed throughoutmuch of the YIn1_xMnxC3)3 YFeOIICuOI4STiOI4SO3 Light BroWn Hexagonal Single layer solid solution range. The key to this color appears to be Mn + ggzo-2célo-4Tlg4o3o go"? g?xagonai 291%? Fly“ in trigonal bipyramidal coordination to oxygen. Without YMnO-2CuO-4TiO-4O3nol uO_45 iO_45 3 Blackac H?xagonalexagona singl?ing e lay?rayer being. bound 'by any particular. theory, '1115. . believed. that the YMnO_3CuO_35TiO_35O3 Black Hexagonal Single layer 35 blue color arises from crystal ?eld splitting associated With g?noaguo?éosoi) Ea? g?xagonai Zing? Fly“ the trigonal bipyramidal coordination and is surprisingly n05 11025-1025 3 ac exagona ing 6 ay?r intense due to a very short apical yn4() bond, e.g., 1.80 YMHO_6C1lO_2TlO_2O3 Black Hexagonal Single layer _ _ YMnO_7CuO_l5TiO_l5O3 Black Hexagonal Single layer 1.95 A, or 1.85-1.90 A. The inventors unexpectedly discov YMnO.8CuO.lTiO.lO3 B1301; H?X?gon?i Sing? iay?r ered that such an intense and bright blue color is characteristic YMnO_9Cu0_O5Ti0_O5O3LuMnO-5CuO-25TiO-25O3 BlackB ac H?xagonalHexagona singl?Sing e lay?rayer 40 of many layered oxides- containing~ - Mn 3+ in- trigonal~ bipyra~ _ YbMnO_5CuO_25TiO_25O3 Black Hexagonal Single layer mldal Coordlnanon YGaO_1InO_8MnO_1O3 Bright Blue Hexagonal Single layer B_ Compositions YGaO-IIDO-7MHO-ZO3 Bright Blue Hexagonal Single layer The present disclosure is also directed to compositions YGaO_1InO_6MnO_3O3 Bright Blue Hexagonal Single layer ______YFeO 11110 8M110 103 Blue Hgxagonal singlg layer comprising a material or materials satisfying at least one of YFeO_2InO_7MnO_1O3 Dark Blue Hexagonal Single layer 45 Formulas I through 6. Such compositions include, for YFeO-3IHO-SMDO-IO3 Gmy/Blu? H?xagonal slngl? layer example, and Without limitation: combinations of materials YFeO_1InO_7MnO_2O3 Blue Hexagonal Single layer . . . . . YFeO_2InO_6MnO_2O3 Dark B1116 Hgxagonal Single laygr satisfying at least one of Formulas I through in combination YFeO_3InO_5MnO_2O3 Grey Hexagonal Single layer With another material or materials that facilitate pigmenting YFeO-IIHO-SMHO-BOB Dark B1116 H?xagonal slngl? lay“ applications. Compositions for pigmenting applications YFeO_2InO_5MnO_3O3 Dark Blue Hexagonal Single layer 50 . 1 d . .nk . 1 d. . . .nk 1 . 1 YFeO_3InO_4MnO_3O3 Dark Blue/Black Hexagonal Single layer Inc u 'epalnts’ 1 S’ Inc u lng Pnnnngl ' S’ p asncsf g asses’ YFeO_1InO_5MnO_4O3 Dark Blue Hexagonal Single layer ceramic products, and decorative cosmetic preparations. ggeo?l?oa?oags gfrkkBlu?/Black g?xagonai Zing? Fly“ Suitable additional materials for use in paints and inks 603 Q3 Q4 3 ac exagona ing e ayer . _ _ _ YF 6011110903 LightYeHOW H exag on 31 S in gl 6 layer include, for example, binders, solvents, additives such as YFeO_2InO_8O3 Light Orange Hexagonal Single layer 55 catalysts, thickeners, stabilizers, emulsi?ers, texturiZers, YFeo.3I110.7O3 Qr?ng? H?X?gon?l slngl? lay?r adhesion promoters, UV stabilizers, ?atteners (i.e., de-gloss “TO-71110303 Light Brown Hexagonal Single layer ing agents), preservatives, and other additives knoWn to those YFeO_8InO_2O3 BroWn Hexagonal Single layer ______YFeO_91nO_lO3 Brown Hgxagonal ginglg layer skilled in the art of pigmenting applications. In some embodi YSCOJMHOBO3 Black H?X?gon?l Single layer ments, the compositions may include more than one material YSCO-2MHO-SO3 Bl'flck Hexagonal Single layer 60 satisfying at least one of Formulas 1-6. In other embodiments, Y1_95EuO_O5MnO_25InO_75O3 Bright Blue Hexagonal Single layer ______Yl_9EuO_lMnO_251nO_75O3 BrightBlug Hgxagonal singlg layer the compositions may include a material satisfying at least YAlO_2OMnO_8OO3.Z(CO3)Z Dark blue Hexagonal Single layer one of Formulas 1-6 in combination With another pigment. YAIO-BOMHO-VOOIJCOQZ Dark blue H?xagonal slngl? layer Suitable additional materials for use in glass products YAl0_4OMnO_60O3,Z(CO3)Z Dark blue Hexagonal Single layer . 1 d f 1 kf .d f .1. YAIOISOMHOISOOLJCOQZ Dark blue H?xagonal Single lay?r inc u e, or examp e,netWor ormers (e.g.,'oxi eso s1 icon, YA1O_GOMHO_4OO3VZ(CO3)Z Dark blue Hgxagonal ginglg layer 65 boron, germanium) to form a highly crosslinked network of YAlO_7OMnO_3OO3,Z(CO3)Z Blue/grey Hexagonal Single layer chemical bonds, modi?ers (e.g., calcium, lead, lithium, sodium, potassium) that alter the netWork structure, and inter US 8,282,728 B2 1 1 12 mediates (e.g., titanium, aluminum, Zirconium, beryllium, midal arrangement are nearly the same at about 2.1 A. In magnesium, Zinc) that can act as both network formers and YMnO3, on the other hand, the apical MniO distances are modi?ers. 1.86 A and the basal plane distances are 2.05 A. Thus, the Suitable additional materials for use in plastic products apical MniO bond lengths in YMnO3 are considerably include, for example, dispersion aids (e. g., Zinc stearate, cal shorter than those in the basal plane. This leads to crystal ?eld cium stearate, ethylene bis-steamide), plasticizers, ?ame splitting of the 3d orbitals energies in YMnO3 as shoWn in retardants, internal mold release agents, and slip agents. FIG. 6. Notably, the e'—>a' energy splitting, Which is the When coloring a ceramic product, the material typically is loWest energy excitation for a d4 cation in the cluster limit, added to a ceramic glaZe composition. Other materials used in depends on the apical M40 bond length through its in?u glaZes include, for example, silica, metal oxides (e.g., ence on the energy of the dZ2 orbital. While the crystal ?eld sodium, potassium, calcium), alumina, and opaci?ers (e.g., stabiliZation associated With a d4 cation in trigonal bipyrami tin oxide, Zirconium oxide). dal coordination has been invoked to explain the stability of hexagonalYMnO3 relative to the competing perovskite struc II. Molecular Structure ture, trigonal bipyramidal is not a common coordination for Mn3+. Some embodiments of materials that satisfy general For In compounds With the general formula, AMnO3, Where A mula 1, AMl_xM'xM"yO3+y, form layers of hexagonal trigo is a rare earth metal, substitution With metal cations such as nal bipyramids. The particular crystal structure is determined, Fe, Co, Ni, Cr, Ti, Ga, or Al is limited before the hexagonal at least in part, by the value of y. When y is 0, the material structure converts to the perovskite structure. This behavior is forms a crystal structure With a single hexagonal layer of 20 seen even When the end-point compound (i.e., complete trigonal bipyramids (see, e.g., FIG. 1A). When y is 1, the replacement of Mn) of the solid solution is stable in the crystal structure has a double hexagonal layer of trigonal hexagonal phase. HoWever, the inventors surprisingly Were bipyramids (see, e.g., FIG. 1B). Similarly, When y is 2, the able to prepare a complete single-phase YInl_xMnxO3 solid crystal structure has a triple hexagonal layer of trigonal solution despite the fact that the siZe mismatch betWeen In3+ bipyramids. 25 and Mn3+ is signi?cant. Without being bound by any particu Although materials With the general formula AM 1 _,€M',€O3 lar theory, this complete miscibility is attributed to the similar (y:0) form a crystal structure With a single hexagonal layer of IniO and MniO basal plane distances in hexagonal YInO3 trigonal bipyramids, the crystal structure can take one of tWo andYMnO3. The large siZe difference betWeen In3 ’' and Mn3+ slightly different con?gurations, as shoWn in FIGS. 2-5. At is manifested only in the apical distances. high temperatures (>600o C.), the materials form a small unit 30 A plot of unit cell edges for theYInHCMrrCO3 solid solution cell (outlined in blue) as shoWn in FIGS. 2 and 4. However, at is shoWn in FIG. 7. FIG. 7 also includes a plot of c/a ratio loWer temperatures, the structure distorts slightly via a ferro versus x. It is clear that the similar basal-plane bond lengths electric transition, forming a larger, polarunit cell (outlined in lead to a Weak variation of a across the solid-solution series. blue) as shoWn in FIGS. 3 and 5. In FIGS. 3 and 5, the smaller HoWever, both c lattice parameter and the c/a ratio decrease unit cell is shoWn outlined in black. The transition betWeen 35 dramatically as x increases because of the large difference in the smaller and larger unit cells is temperature dependent and apical In4O and Mn4O bond lengths. readily reversible. Edge ‘a’ is the Width of the unit cell. In the The blue color of the poWders is evident in FIG. 8 for even small unit cell, a is the distance betWeen tWo basal, or equa very loW values of x. To understand the origin of this blue torial, oxygen atoms. Edge ‘c’ is the height of the unit cell. As color, diffuse re?ectance spectra Were measured (FIG. 9), ?rst shoWn in FIGS. 4-5, c is the height of three layers of A atoms 40 principles density functional theory (DFT) calculations Were alternating With tWo layers of trigonal bipyramids. In the performed With the LSDA+U method, Which has been shoWn small unit cells, a typically is 3.50-3.70 A, more typically previously to give reliable results for YMnO3. (Fennie et al., 3.60-3.65 A. In the large unit cells, a typically is 5.5-7.0 A, Phys. Rev. B., 72: 100103 (2005).) With reference to FIG. 9, at more typically 6.0-6.5 A. Both the small and large unit cells loW doping concentrations, there is a strong, narroW (~1 eV have similar values for c, typically 10-13 A. 45 Width) absorption centered at ~2 eV that absorbs in the red BothYInO3 andYMnO3 are knoWn in the common orthor green region of the visible spectrum. The absorbance then hombic and centric form of the perovskite structure (i.e., a decreases betWeen 2. 5 and 3 eV With a second onset near 3 eV. crystalline structure of the formula A2+B4+X32+, Where the The lack of absorption in the 2.5-3 eV (blue) region of the ‘A’ cations are larger than the ‘B’ cations; X is usually oxygen spectrum results in the blue color. As the concentration of Mn and is in a face-centered position in the crystal), but they also 50 increases, the loWer-energy absorption peak broadens and the can be prepared in an acentric hexagonal structure (FIG. 1A) higher-energy onset shifts to loWer energy, consistent With the that is not perovskite related. This hexagonal structure com gradual darkening of the samples toWard navy blue. In pure prises layers of Y3 + ions separating layers of comer-shared YMnO3, absorption occurs throughout the entire visible MO5 trigonal bipyramids (MIIn, Mn). In this structure, region, resulting in the black color. Mn/In is located in trigonal bipyramidal MnOS/InO5 units 55 DFT calculations of the densities of states and optical With corner sharing of the trigonal basal plane oxygen atoms. properties of the fully relaxed end-point compounds and HoWever, the Mn/In atoms are not located in the exact centers selected intermediates indicate that the peak at 2 eV arises of the trigonal bipyramids; they are displaced in both the ab from the transition betWeen the valence-band maximum, con basal plane and along the c axis. This structure has been of sisting of Mn 3dx2_y2x=y states strongly hybridized With 0 2pm considerable recent interest because it exhibits an unusual 60 states, and the loWest unoccupied energy level, Which in form of improper geometric ferroelectricity accompanied by lightly Mn-doped YInO3 is a narroW band formed from the tilting of the MOS polyhedra. Such ferroelectricity is compat Mn 3dx2 state that lies in the band gap ofYInO3. (The absence ible With M-site magnetism and therefore alloWs multiferroic of midgap Mn 3dZ2 states in pure YInO3 leaves it colorless.) behavior. Notably, in the local D3h symmetry of the trigonal bipyra Although hexagonal YInO3 and YMnO3 are isostructural, 65 mids, the d-d component of this transition (betWeen symme there is a signi?cant difference betWeen the tWo structures. In try labels a' and e' in FIG. 6) is formally symmetry-alloWed the case of YInO3, all In4O distances in the trigonal bipyra according to the Laporte selection rule, Whereas the e"%a' US 8,282,728 B2 13 14 transition is symmetry-forbidden. This results in a high tran axis, Which is the polar axis, Were found to be of the same sition probability and intense absorption. The strong d-d magnitude as in YMnO3. Thus, another conclusion from this absorption is in striking contrast to the behavior in the structure analysis is that the degree of ferroelectric distortion approximate Oh crystal ?eld environment of perovskites, in YMnO_63InO_37O3 is essentially the same as in YMnO3. Where it is formally symmetry-forbidden. In Oh symmetry, HoWever, ?rst-principles calculations suggest that the polar hybridization With ligands or structural distortions is required iZation might be substantially suppressed from the values in to circumvent the dipole selection rules, and d-d transitions the end-member compounds due to frustration of the coop are usually Weak. Indeed, no blue color Was seen When Mn3+ erative tilting by the different siZes of the MOS polyhedra. Was substituted into YGaO3 or YAlO3 With the perovskite Mn3 + also Was substituted into another structure With trigo structure, Where the Mn3+ Would be in an environment With nal bipyramidal sites, the YbFe2O4 structure. This structure approximate Oh symmetry. (FIG. 1B) has layers of rare-earth cations alternating With The higher-energy peak is assigned to the onset of the double layers of MOS trigonal bipyramids. As inYMnO3, the transition from the 0 2p band to the Mn 3dZ2 band. With polyhedral in each MO3 plane share comers through their increasing Mn concentrations, the calculations indicate that basal-plane oxygen atoms. Here, hoWever, polyhedral in the the Mn 3d levels (particularly the loWest unoccupied state, second plane share edges betWeen apical and basal oxygens corresponding to the 3dZ2 band) broaden substantially, caus With those in the ?rst plane. As inYMnO3, the topology of the ing the absorption peaks to become broader. layering should alloW the apical bond lengths to adopt differ To determine Which structural features correlate With the ent values for the different M-site cations Without introducing blue color, the structural properties of some intermediate large strain energies into the lattice. AlthoughYbFe2O4 is not compositions Were investigated. DFT calculations on the 20 a suitable host because of its black color related to Fe2"/Fe3+ relaxed structures for both Y8Mn2In6O24 and Y8Mn6In2O24 mixed valency, there are several oxides With this structure that units shoW that While the basal plane MniO and In4O are transparent throughout the visible spectrum.7 distances in these intermediates are similar to each other to Additional compositions With this structure include com those of the end members, the apical Mn4O and In4O pounds With the general formula AMM"yO3+y Where A, M, distances are very different from each other, maintaining 25 and M" are de?ned as in Formula 2, such as ScAlMgO4, values close to those of the respective end members. Since the ScGaMgO4, ScGaZnO4, LuGaMgO4, and InGaMgO4. Add energy of the dZ2 state relative to the valence-band maximum ing manganese to these compounds produces manganese (III) is determined primarily by the Mn4O apical bond length, materials according to Formula 2 With a blue color. For this explains the lack of shift in the energy of the 2 eV instance, an intense blue color is produced With 5% doping of absorption peak as a function of Mn concentration. If Mn is 30 Mn3+ to produce a material With the formula arti?cially inserted into the YInO3 structure Without alloWing AMO_95MnO_O5M"yO3+y, e.g., ScAlO_95MnO_5MgO4. Thus, the the structure to relax to its energy minimum, the dzz peak shifts blue color appears to be a general characteristic of Mn3+ in a to considerably loWer energy, and the calculated absorption trigonal bipyramidal site in oxides, provided that structural spectrum changes markedly. features such as layering alloW for the appropriate apical The structure of YMnO_63InO_37O3 Was re?ned from single 35 Mn4O bond length. crystal x-ray diffraction data in space group P63cm, the same space group used for hexagonal YMnO3 and YInO3. The III. Methods of Making the Materials structure re?ned normally except for displacement param eters for one of the apical O atoms, suggesting the presence of Polycrystalline materials, particularly chromophoric static disorder arising from the different In4O and Mn4O 40 materials, according to Formulas 1-6 are prepared by heating distances. There are tWo extreme possibilities for these apical mixtures of reactants, such as metal oxides, in air. For oxygen atoms in the solid solution. One is that the IniO and example, poWders of Y2O3, Mn2O3, and In2O3 can be mixed Mn4O distances of the end members Would be maintained in thoroughly in desired quantities and heated to produceYInl_,C the solid solution. The other is that the O atom in the apical MnxO3. position is not disordered in the solid solution but instead 45 In certain disclosed embodiments, the material has a color accepts a position intermediate betWeen that expected for the that varies along a color continuum to form a homologous end members. The lack of a signi?cant shift in energy of the series as the value of x in Formulas 1-6 increases. For 2 eV absorption peak as a function of x in YIn1_,€Mn,€O3 example, the material having the formula YIn1_,€Mn,€O3 phases indicates that the short apical Mn4O distances are exhibits an intense blue color. A shoWn in FIG. 8, the blue maintained in the solid solution. This conclusion is supported 50 color darkens and eventually appears black as x increases. by the failure of an ellipsoid to adequately de?ne the electron Thus, a material having a desired color along the continuum density at an apical 0 site. Thus, the YMnO_63InO_37O3 struc can be prepared by selecting the value of x corresponding to ture Was re?ned With two 0 atoms at each apical site having the desired color, and combining the reactants in stoichiomet occupation values ?xed on the basis of the Mn/In ratio. The ric quantities according to the selected value of x. re?nement converged With shorter distances for the sites With 55 In some embodiments, the reactants are dried, e. g., at 800 the higher occupation. Apical Mn4O distances of 1.86 A and 10000 C., before mixing. The reactants can be mixed by any 1.89 A and apical In4O distances of2.05 A and 2.20 A Were suitable means, including dissolving the reactants in a suit extracted. Because of the complication of overlapping elec able solvent or by mechanical mixing (e.g., mortar-and tron density, this re?nement of the apical O atoms in the split pestle, ball milling). In certain embodiments, the poWders model can only be considered an approximation. Nonethe 60 may be mixed, e. g., by mortar and pestle or using an agate ball less, the success of this split atom re?nement is highly com mill, under a suitable liquid in Which they are substantially pelling evidence that the apical O atoms do not reside at some insoluble, e.g., a loWer alkyl (i.e., 1-10 carbon atoms) alcohol average position for both Mn and In trigonal bipyramids. such as methanol or ethanol. The liquid is evaporated, and the Furthermore, these values are in excellent agreement With the residual solids are ground into a poWder. ?rst-principles calculations. Violations of Friedel’s laW in the 65 In some embodiments, the materials are prepared by dis diffraction data con?rm a polar space group. Relative to the solving hydrated nitrate salts of the metals in deioniZed Water. paraelectric structure, displacements of atoms along the c An organic acid (e.g., citric acid) is added to the solution, and US 8,282,728 B2 15 1 6 the solution then is neutralized With an aqueous base (e.g., for 10 hours (Examples 32-34, 46, 47) or 12 hours (Examples ammonium hydroxide). The solution is evaporated to form a 35-45). The calcined pellets Were reground, pressed into pel Viscous gel, Which subsequently is combusted. In a Working lets and ?red at 1050° C. for 12 hours (Examples 46, 47) or 18 embodiment, the gel Was combusted at 250° C. for 2 hours. hours (32-45). The calcined pellets Were reground, pressed In some embodiments, the mixed poWders are pressed into into pellets and ?red a third time at 1050° C. for 12 hours pellets. For example, the poWders may be pressed into pellets (Examples 32, 33, 35-41) or 18 hours (42-45). The calcined using a pressure of 500 psi. The mixed, and optionally pel pellets Were reground, pressed into pellets and ?red a fourth leted, poWders are calcined. In some embodiments, the mixed time at 1050° C. for 12 hours for Examples 32, 33, 35-41 and poWders are calcined at temperatures from about 700° C. to at 1100° C. for Examples 42-45. The ramping rate of each about 1500° C. for about 2 hours to about 20 hours. Calcina heating cycle Was 300° C./hr. Cell parameters a and c Were tion can be performed in air. Typically, the material undergoes determined by X-ray diffraction as described in Example 104. multiple calcinations. The material may be re-ground and re-pelleted betWeen each calcination step. In a Working Examples 48-62 embodiment, pellets comprisingYInl_,€Mn,€O3 Were calcined for tWelVe hours in air at 1200° C., and tWelVe hours in air at 1300° C. With intermediate grinding and re-pelleting; in some instances a third calcination for tWelVe hours in air at 1300° C. Was performed. Other synthesis techniques such as sol-gel, co-precipita The compositions of YGaOJInOS?IVIrrCOy YFeXInO_9_,C tion, hydrothermal including supercritical conditions, spray 20 MnO_lO3, YFexInO_8_xMnO_2O3, YFexInO_7_xMnO_3O3, drying, freeZe drying, high-temperature spray pyrolysis (e.g., YFeXInO_6_XMnO_4O3 (012x203) of Examples 48-62 Were TiO2 and ZnO) can be used to prepare poWders; these tech made using the folloWing procedure. For each Example, niques may be especially suitable for controlling particle siZe. appropriate amounts of the starting oxides, Y2O3, Ga2O3, In2O3, Mn2O3, and Fe2O3 Were Weighed according to the IV. Examples 25 stoichiometric ratios and mixed thoroughly in an agate mor tar. The gram amounts for 1 g sample siZes of the starting Examples 1-31 materials used are shoWn in Table 5. In each Example, the mixed poWder Was pressed into pellets and Was ?red in air at 1200° C. for 12 hours. The calcined pellet Was reground, 30 pressed into pellets and ?red again at 1300° C. for 12 hours. The calcined pellet Was reground, pressed into pellets and The compositions of YInl_,€Mn,€O3 (0.05 5x509), Dy ?red again at 1300° C. for 12 hours. The ramping rate of each Inl_xMnxO3 (012x208), HoInl_xMnXO3 (012x209), heating cycle Was 300° C./hr. Cell parameters a and c Were ErIn1_,€Mn,€O3 (x:0.1, 0.2, 0.5, 0.8) of Example 1-31 Were determined by X-ray diffraction as described in Example 104. made using the folloWing procedure. For each Example, 35 appropriate amounts of the starting oxides, Y2O3, Dy2O3, Examples 63-67 H0203, Er2O3, In2O3 and Mn2O3 Were Weighed according to the stoichiometric ratios and mixed thoroughly in an agate YSc l_xMrrcO3, YInl _xFexO3 mortar. The gram amounts for 0.5-6 g sample siZes of the starting materials used are shoWn in Table 2. In each Example, 40 The compositions of YScHCMnXO3 (082x209) and the mixed poWder Was pressed into pellets and Was ?red in air YInl_xFexO3, (012x203) of Examples 63-67 Were made at 1200° C. for 12 hours. The calcined pellet Was reground, using the folloWing procedure. For each Example, appropri pressed into pellets and ?red again at 1300° C. for 12 hours. ate amounts of the starting oxides, Y2O3, Mn2O3, Sc2O3, In some cases it Was necessary to repeat grinding and ?ring in In2O3, and Fe2O3 Were Weighed according to the stoichio air at 1300° C. for 12 hours. The ramping rate of each heating 45 metric ratios and mixed thoroughly in an agate mortar. The cycle Was 300° C./hr. Cell parameters a and c Were deter gram amounts for 0.5-1 g sample siZes of the starting mate mined by X-ray diffraction as described in Example 104. rials used are shoWn in Table 5. In each Example, the mixed poWder Was pressed into pellets and Was ?red in air at 1200° Examples 32-47 C. for 12 hours. The calcined pellet Was reground, pressed 50 into pellets and ?red again at 1300° C. for 12 hours. The ramping rate of each heating cycle Was 300° C./hr. Cell parameters a and c Were determined by X-ray diffraction as described in Example 104.

55 Examples 68-69 The compositions of YCuO_5TiO_5O3, Y(CuO_5TiO_5)l_,C MnxO3 (012x209), YCuO_45TiO_45MO_lO3 (MIAl, Ga), Y1—xEuxMnO.25InO.75O3 Y(CuO_5TiO_5)l_,€Fe,€O3 (x:0.1, 0.2), LnCuO_25TiO_25MnO_5O3 (LnIYb, Lu) of Examples 32-47 Were made using the folloW The compositions of Yl_,€EuxMnO_25InO_75O3 (x:0.05 and ing procedure. For each Example, appropriate amounts of the 60 0.1) of Examples 68-69 Were made using the folloWing pro starting oxides, Y2O3, Lu2O3, Yb2O3, CuO, TiO2, Mn2O3, cedure. For each Example, appropriate amounts of the start Fe2O3, Ga2O3, and A1203 Were Weighed according to the ing oxides, Y2O3, Mn2O3, Sc2O3, In2O3, and Fe2O3 Were stoichiometric ratios and mixed thoroughly in an agate mortar Weighed according to the stoichiometric ratios and mixed for approximately 15 minutes under ethanol. The gram thoroughly in an agate mortar. The gram amounts for 0.5-1 g amounts for 1.5-2.5 g sample siZes of the starting materials 65 sample siZes of the starting materials used are shoWn in Table used are shoWn in Tables 3 and 4. In each Example, the mixed 5. In each Example, the mixed poWder Was pressed into poWder Was pressed into pellets and Was ?red in air at 9000 C. pellets and Was ?red in air at 1300° C. for 12 hours. The US 8,282,728 B2 17 18 calcined pellet Was reground, pressed into pellets and ?red oxides Were Weighed according to the desired stoichiometric again at 1300° C. for 12 hours. The ramping rate of each ratios. The gram amounts of the starting materials used are heating cycle Was 300° C./hr. Cell parameters a and c Were shoWn in Table 7. In general, the poWders Were ball-milled for determined by X-ray diffraction as described in Example 104. 2 hours and then calcined at 1,000° C. for 5 hours. Following calcination, the poWders Were ball-milled for 2 hours, pressed Examples 70-76 into pellets and then calcined again under the conditions shoWn in Table 7. The ramping rate of each heating cycle Was 1 —xMnxO3 —Z(CO3 )2 300° C./hr. The compositions ofYAll_xMnxO3_Z(CO3)Z (022x208; Example 104 0.022; 1 .0) of Examples 70-76 Were made using the folloW ing procedure. For each Example, appropriate amounts of the Synthesis and CharacteriZation of YIn1_xMnxO3 starting hydrated nitrates, Y(NO3)3.6H2O, Al(NO3)3.9H2O, Materials Mn(NO3)2.4H2O Were Weighed according to the stoichio metric ratios and dissolved in a small amount of deioniZed Synthesis Water. The gram amounts for 1.5 or 4 g sample siZes of the Polycrystalline samples Were prepared by heating mixtures starting materials used are shoWn in Table 6. In each Example, of reactants in air. Reactants Were Y2O3 (Nucor: Research the solution Was heated to 60° C. With stirring for about 15 Chemicals, 99.99%), Mn2O3 (JMC, 98%+), and In2O3 (Ald minutes. Citric acid (C6H8O7) Was then added to the solution rich, 99.99%). PoWders of YZO3 Were dried at 850° C. before and alloWed to dissolve under stirring. The solution Was neu 20 Weighing. Appropriate quantities of reactants Were mixed traliZed With aqueous NH4OH. The solution Was evaporated thoroughly under ethanol in an agate mortar. Intimately at 90° C. for several hours until a viscous gel is formed. The mixed poWders Were pressed into pellets under a pressure of dried gel Was combusted at 250° C. for 2 hours. The resulting approximately 500 psi. The pellets Were calcined for tWelve black product Was ground, and the poWder Was heated at 750° hours once in air at 1200° C., and tWice in air at 1300° C. With C. for 10 hours in air. The poWder Was then pressed into 25 intermediate grinding. Ramp rates Were 300° C./hr. pellets, and the pellets Were heated to 900° C. for 12 hours in Single crystals Were groWn in a PbF2 ?ux using a 10-fold air, reground, pressed into pellets, and heated at 900° C. for 12 excess by Weight of ?ux. The mixture Was placed in a plati hours in air. The ramping rate of each heating cycle Was 300° num crucible, Which Was placed in an alumina crucible and C./hr. Cell parameters a and c Were determined by X-ray capped. The mixture Was rapidly heated in air to 840° C. diffraction as described in Example 104. 30 (melting point of PbF2) and held for 3 hours. The sample Was then heated sloWly (5° C./hr) to 950° C. (the temperature at Examples 77-80 Which PbF2 evaporates), and held for 6 hours before cooling to room temperature at 300° C./hr. The ?ux Was dissolved in YFel_,€InxO3 nitric acid. The product consisted of thin black hexagonal 35 plates. The compositions of YFe1_,€InxO3 (012x203) of Single Crystal and PoWder Diffraction Examples 77-80 Were made using the folloWing procedure. X-ray poWder diffraction @(RD) patterns Were obtained For each Example, appropriate amounts of the starting With a Rigaku MiniFlex II diffractometer using Cu KO. radia hydrated nitrates, Y(NO3)3.6H2O, Fe(NO3)3.9H2O, In tion and graphite monochromator. Single crystal X-ray dif (NO3)3.H2O Were Weighed according to the stoichiometric 40 fraction data Were collected on a Bruker SMART APEXII ratios and dissolved in a small amount of deioniZed Water. The CCD system at 173 K. A standard focus tube Was used With an gram amounts for 1.5 g sample siZes of the starting materials anode poWer of 50 kV at 30 mA, a crystal-to-plate distance of used are shoWn in Table 6. In each Example, the solution Was 5 .0 cm, 512><512 pixels/frame, beam center (256.52, 253.16), heated to 60° C. With stirring for about 15 minutes. Citric acid total frames of 6602, oscillation/frame of 0.501, exposure/ (C6H8O7) Was then added to the solution and alloWed to 45 frame of 10.0 s/frame and SAINT integration. A subsequent dissolve under stirring. The solution Was neutraliZed With SADABS correction Was applied. The crystal structure Was aqueous NH4OH. The solution Was then evaporated at 90° C. solved With the direct method program SHELXS and re?ned for several hours until a viscous gel is formed. The dried gel With full-matrix least-squares program SHELXTL. (G. M. Was combusted at 250° C. for 2 hours. The resulting black Sheldrick, SHELEXTL, Version 6.14, Bruker Analytical product Was then ground, and the poWder Was heated at 700° 50 X-ray Instruments, Inc., Madison, Wis., 2003.) Crystallo C. for 18 hours in air. For x:0.3, an additional heating at 700° graphic results forYInO_37MnO_63O3 are summariZed in Tables C. for 20 hours in air as poWder Was required. The ramping 8-11. The crystal Was found to be tWinned With an up/doWn rate of each heating cycle Was 300° C./hr. Cell parameters a polariZation ratio of 0.3 5 (3). X-ray poWder diffraction (XRD) and c Were determined by X-ray diffraction as described in patterns Were obtained With a Rigaku MiniFlex II diffracto Example 104. 55 meter using Cu KO. radiation and graphite monochromator. PoWder diffraction patterns from 10-60° 20 for the YInl_,C Examples 81-103 MnxO3 solid solution With values of x from 0.0 to 1.0 can be seen in FIG. 10. The bottom pattern is YMnO3, and the top pattern is YInO3.

TABLE 8

Crystal data and structure re?nement YInO_37MnO_63O3 Formula Weight 214.00 The hexagonal double-layer and triple-layer compositions 65 Temperature 173(2) K of Examples 81-103 Were made using the folloWing proce Wavelength 0.71073 A dure. For each Example, appropriate amounts of the starting US 8,282,728 B2 1 9 20 TABLE 8-continued TABLE 11

Crystal data and structure re?nementYInO_37MnO_63O3 Anisotropic displacement parameters (A2 x 103).”

Crystal system Hexagonal U11 U22 U33 U23 U13 U12 Space group P63cm Y1 2(1) 2(1) 6(1) 0 0 1(1) Unit cell dimensions a = 6.1709(6) A Y2 6(1) 6(1) 28(1) 0 0 3(1) C = 11.770(2) A Mn/In 7(1) 5(1) 5(1) 0 -1(1) 2(1) Volume 388.17(9) A3 03 33(7) 33(7) 5(7) 0 0 17(3) Z 6 04 3(3) 3(3) 33(7) 0 0 1(1) Density (calculated) 5.437 mg/m3 Absorption coef?cient 28.267 mm’l The anislqtropic displacement factor exponent takes the form: —27l:2[h2 a*2Ull + . . . + 2 h k a* b* U ] F(000) 576 “Split atoms O1, O1‘, O2, and O2l Were re?ned With isotropic displacement parameters. Crystal size 0.05 x 0.03 x 0.01 mm Theta range for data collection 3.46 to 28.310 First-Principles Calculations Index ranges —7 2 h 2 8, —7 2 k E First-principles calculations Were performed With plane 7, —15 2 l 2 15 Wave density functional theory using the Vienna Ab-initio Reflections collected 3766 Independent reflections 363 [R(int) = 0.0263] Simulation Package (VASP). (Kresse, G., and Furthmueller, Completeness to theta = 28.310 98.0% 20 1., Phys. Rev. B 54, 11169-11186 (1996); Kresse, G., and Absorption correction Semi-empirical from equivalents 1oubert, D., Phys. Rev. B 59, 1758-1775 (1999).) Exchange Max. and min. transmission 0.7653 and 0.3322 and correlation effects are treated on the level of LSDA+U, Re?nement method Full-matrix least-squares on F2 With an on-site Coulomb repulsion U:5.0 eV and an intra Data/restraints/parameters 363/0/31 atomic exchange splitting of 1:0.5 eV for Mn d states. Goodness-of-?t on F2 1.178 25 (Liechtenstein, A. I., Anisimov, V. I., and Zaanen, 1., Phys. Final R indices [I > 2sigma(I)] R1 = 0.0219, WRZ = 0.0407 Rev. B 52, R5467-R5470 (1 995).) A global antiferromagnetic R indices (all data) R1 = 0.0288, WRZ = 0.0438 ordering With ferromagnetic Mn planes Was adopted for the Largest diff. peak and hole 0.934 and -0.629 e/A3 simulations. Intermediates Within periodic boundary condi tions Were studied using the supercell approach With lattice 30 constants taken from experimental values presented in FIG. 7. The 40-atom supercells permit concentrations of x:0.0, 0.25, TABLE 9 0.5, 0.75 and 1.0 While maintaining equal numbers of In and Atomic coordinates and equivalent isotropic displacement Mn atoms in each layer. An ordering Was chosen in Which the parameters (A2 x 103). minority component Was maximally separated in space; thus, 35 the possibility of In or Mn clustering Was ignored. X y Z U091) All structures Were initialized in the centrosymmetric P63/ Y1 0 0 0 3(1) mmc space group and all atomic degrees of freedom Were Y2 1/3 Z/3 0.9636(1) 13(1) optimized until forces Were less than 0.1 meV/A. This strict MH/Ina 0.3342(4) 0 0.7211(4) 6(1) 01 0.322(4) 0 0.879(3) 21(6) 40 tolerance alloWed accurate study of delicate features of the 01' 0.289(5) 0 0.893(2) 0(6) atomic structure, such as tiltings of the polyhedra that are 02 0.635(3) 0 0.061(2) 0(3) responsible for ferroelectricity. (Fennie, C. 1., and Rabe, K. 02' 0.655(5) 0 0.034(2) 7(6) 03 0 0 0.202(2) 24(4) M., Phys. Rev. B 72, 100103(4) (2005).) 04 1/3 Z/3 0.749(1) 13(3) Summary of Convergence Parameters: 45 U(eq) is de?ned as one third ofthe trace ofthe onhogonalized U17 tensor. 1) 450 eV plane Wave cutoff (33.1 Ry, 16.5 Ha) “Re?ning occupation parameters gave an Mn/In ratio of 1.70 for this site. The Ol/Ol' and O2/O2' occupancy ratios are ?xed at the Mn/In ratio. 2) 3><3><2 Monkhorst-Pack k-point mesh containing kXIKyIO TABLE 10 3) Electronic total energy converged to 1x10‘9 eV 50 Bond lengths (A) 4) Average ionic force relaxed to 20.5 meV/A Results are summarized in Tables 12 and 13. Y14O1 x 3 244(3) Y14O1' x3 2.18(3) Y14O2 x 3 236(2) TABLE 12 Y14O2' x 3 217(3) 55 Y14O3 2.38(2)/3.51(2) Distances and polyhedral volumes obtained after relaxation. Multiple Y24O1 x 3 232(2) entries indicate structural disorder Within the simulation cell. Y24O1' x 3 236(2) Y24O2 x 3 228(1) In4OaP In4Oeq MniOaP Mn4Oeq Y24O2' x 3 218(1) Compound (A) (A) (A) (A) Y24O4 x 3 2.53(1)/3.35(1) Mn/In4O1 1.86(3) Y6In6O18 2.11,2.13 2.13,2.14 N/A N/A Mn/In4O1' 2.05(3) Y8In8O24 2.09, 2.12 2.13, 2.13 N/A N/A Mn/In4O2 1.89(2) Y8Mn2In6O24 2.10, 2.12 2.14 1.91, 1.93 2.00, 2.04 Mn/In4O2' 2.20(3) Y8Mn6In2O24 2.08 2.16, 2.18 1.88, 1.91 2.01, 2.08 Mn/In4O3 2.074(3) Y8Mn8O24 N/A N/A 1.85, 1.88 2.03, 2.11 Mn/In4O4 x 2 2.080(3) 65 Y6Mn6O18 N/A N/A 1.87 2.04, 2.11