DOCSLIB.ORG

Appendix a Properties of Yttrium–Iron–Garnet (YIG)

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Appendix a Properties of Yttrium–Iron–Garnet (YIG) Appendix A Properties of Yttrium–Iron–Garnet (YIG) Structure and Physical Properties Chemical formula Y3Fe5O12 Crystal structure Cubic Number of formula units per unit cell 8 Lattice constant (25 ◦C) 12.376 A˚ Mass density (25 ◦C) 5172 kg/m3 Octahedral Sublattice 27 −3 Site density Na 8.441 × 10 m Angular momentum Ja 5/2 Land´e g factor ga 2 Magnetization at 0 K Ma (0 K) 391.5 kA/m Tetrahedral Sublattice 27 −3 Site density Nd 12.66 × 10 m Angular momentum Jd 5/2 Land´e g factor gd 2 Magnetization at 0 K Md (0 K) 587.2 kA/m Molecular Field Constants [1] Octahedral λaa 735.84 Tetrahedral λdd 344.59 Nearest-neighbor λad 1100.3 Phenomenological Exchange Constant [2] 2 −16 2 Defined by hex = λex∇ m (3.104) λex 3 × 10 m Macroscopic Magnetic Properties Magnetization at 0 K Mtot (0 K) 196 kA/m Magnetization at 298 K Mtot (298 K) 140 kA/m Curie temperature Tc 559 K 333 334 References Anisotropy Constants 3 First-order cubic (4.2 K) [3] Kc1 (4.2 K) −2480 J/m 3 First-order cubic (295 K) [3] Kc1 (295 K) −610 J/m 3 Second-order cubic (4.2 K) [4] Kc2 (4.2 K) −118.0J/m 3 Second-order cubic (273 K) [4] Kc2 (273 K) −26.0J/m Optical Properties [5–7] Refractive index (1.2 μm) n 2.2 Faraday rotation (1.2 μm) φF 240 deg/cm Absorption coefficient (1.2 μm) α 0.069 cm−1 μ 2 − × −4 Cotton–Mouton tensor elements (1–3 m) g44MS 1.14 10 2 × −5 ΔgMS 5.73 10 Cotton–Mouton rotation (1.14 μm) ΦCM −160 deg/cm References [1] E. E. Anderson, “Molecular field model and magnetization of YIG,” Phys. Rev., vol. 134, p. A1581, 1964. [2] E. H. Turner, “Interaction of phonons and spin waves in yttrium iron garnet,” Phys. Rev. Lett., vol. 5, p. 100, 1960. [3] P. Hansen, “Anisotropy and magnetostriction of gallium-substituted yt- trium iron garnet,” J. Appl. Phys., vol. 45, p. 3638, 1974. [4] P. Escudier, “L’anisotropie de l’aimantation; un param´etre important de l’´etude de l’anisotropie magn´etocrystalline,” Ann. Phys. (Paris), vol. 9, p. 125, 1975. [5] M. J. Weber, Ed., CRC Handbook of Laser Science and Technology, Vol. IV Optical Materials Part 2: Properties. Boca Raton, FL: CRC Press, 1986, p. 291. [6] R. V. Pisarev, I. G. Sinii, N. N. Kolpakova, and Y. M. Yakovlev, “Magnetic birefringence of light in iron garnets,” Sov. Phys. JETP, vol. 33, p. 1175, 1971. [7] G. A. Smolensky, R. V. Pisarev, I. G. Sinii, and N. N. Kolpakova, “Cotton- Mouton birefringence of ferrimagnetic garnets,” J. Physique Colloque, vol. C1 32, pp. c1–1048, 1971. Appendix B Currents in Quantum Mechanics B.1 Density of States The valence electrons in a metal can be modeled as free electrons contained in a box the size of the sample. Because of the boundary conditions at the faces of the box, the allowed values of wave number k are quantized. The actual conditions at the surface of a metal may be very complicated, but much of solid-state physics depends primarily on the fact that the modes are quantized, rather than on exactly what the boundary conditions of a particular sample happen to be. Consequently, it is common to make the simple assumption of periodic boundary conditions. In this assumption, the wave function of an electron at x = L should equal to that at x = 0, where L is the length of the sample along the x-direction. For this to be true, we have exp(ikL) = exp(0) = 1, which gives the discrete values of wave number k =2πn/L, where n is an integer. In k space, the total number of states N in a sphere of radius |k| is given by the volume of the sphere divided by the volume occupied by one state. Thus 4 1 4πk3L3 N =2 πk3 =2 , (B.1) 3 (2π/L)3 3(2π)3 where we have assumed the sample is a cube with length L on each side so that 3 the minimum volume in k space is ΔkxΔkyΔkz =(2π/L) . The factor of 2 accounts for the degeneracy in the energy of spin-up and spin-down electrons.1 In the free electron approximation, the Hamiltonian H is merely the kinetic energy operator (cf. Table 1.1) p2 2 H = = − ∇2 , (B.2) 2m 2m 1 When we consider ferromagnetic metals, this degeneracy is lifted by the inter- action with the internal exchange field causing a splitting of the energy band diagram. 335 336 Appendix B Currents in Quantum Mechanics and when we assume an electron wavefunction of the form ψ ∼ eik·r,the Schr¨odinger equation Hψ = Eψ yields 2k2 = E. (B.3) 2m Combining (B.1) and (B.3), the number of states with energy less than E can be written 4πL3 2m 3/2 N =2 E3/2. (B.4) 3(2π)3 2 The density of states is defined as the number of states per unit energy, or dN g(E)= . (B.5) dE Thus, the density of states is given by 4πL3 2m 3/2 3 g(E)=2 E1/2 (B.6) 3(2π)3 2 2 L3 2m 3/2 √ = E. (B.7) 2π2 2 The Fermi energy is defined as the highest occupied energy state by an electron, at absolute zero temperature. Interactions at higher temperatures 2 2 typically occur near the Fermi energy, EF = kF/(2m), since electrons at the Fermi energy have nearby empty states. Consequently, the current is often calculated at the Fermi energy while assuming the parabolic band approxi- mation g(E) ∝ E1/2. Multiplying and dividing (B.7) by E and comparing the result with (B.4), we see that the relationship between the Fermi energy and the density of states can be expressed 3 N g(EF)= . (B.8) 2 EF At finite temperature, some of the electrons will be excited to states above the Fermi level. In this case, the density of states is related to the number of particles by ∞ N = g(E)f(E)dE , (B.9) 0 where − − 1 f(E)= 1+e(E EF)/(kBT ) (B.10) is the Fermi–Dirac distribution describing the probability of finding an elec- −23 tron with energy E at temperature T and kB =1.38 × 10 J/Kisthe Boltzmann constant. B.2 Electric and Spin Current Densities 337 Note that the above expressions assume degenerate spin-up and spin-down subbands. In a ferromagnetic metal, the molecular field interacting with the electron spin splits the bands as illustrated in Figure 10.1. If the magnetization is oriented upwards, then the Hamiltonian with the effects of the molecular field is (cf. Eq. (2.30)) −2 d 2 H = + μ μ σH , (B.11) 2m dx 0 B m where Hm is the molecular field and σ = ±1. Defining Em = μ0μBσHm,the density of states for the spin subbands can be expressed 1 g (E)= g (E − σE ) , (B.12) σ 2 m and the total density of states is given by g(E)= gσ(E) (B.13) σ = g↑(E)+g↓(E) (B.14) 1 = [g (E − E )+g (E + E )] . (B.15) 2 m m (B.16) B.2 Electric and Spin Current Densities Consider ψ to be a solution of the 1D Schr¨odinger equation ∂ψ 2 i = − ∇2ψ. (B.17) ∂t 2m Multiplying (B.17) by ψ∗ and subtracting the complex conjugate of the re- sulting equation, we obtain ∂ −i (ψ∗ψ)+ ∇·[ψ∗∇ψ − ψ∇ψ∗]=0. (B.18) ∂t 2m In obtaining (B.18), we have used the vector identity ∇·(f∇g)=∇f ·∇g + f∇2g. (B.19) If we define the probability density of finding an electron as ψ∗ψ,wecan express the charge density as ρ = qψ∗ψ. We can also define a current density j that satisfies the conservation equation ∂ρ + ∇·j =0. (B.20) ∂t 338 Appendix B Currents in Quantum Mechanics Multiplying (B.18) by the electronic charge q and comparing with (B.20), we make the identification −iq j = [ψ∗∇ψ − ψ∇ψ∗] 2m (B.21) q = Im(ψ∗∇ψ). m √ Choosing ψ =1/ keikx for the 1D case ensures the normalization dψ Im ψ∗ =1. (B.22) dx Under the two-band approximation, we treat the spin-up and spin-down carriers as being independent. Under this two-channel approximation, we can borrow standard techniques from quantum mechanics to solve for the prob- ability of carrier transmission across an interface, or even through a barrier with multiple interfaces. B.3 Reflection and Transmission at a Boundary Consider an electron that is incident on a planar interface between two media as illustrated in Figure B.1. The electron will be reflected with probability Medium 1 Medium 2 t r x Fig. B.1. Geometry for calculating the reflection and transmission coefficients of a particle at a boundary between two materials. amplitude r, and transmitted with probability amplitude t. In medium 1, the wave function is ψ1 = ψinc + ψref (B.23) 1 − = √ eik1x + re ik1x , (B.24) k1 (B.25) while in medium 2, the wave function is B.4 Tunneling Through a Barrier 339 t ik2x ψ2 = ψtr = √ e . (B.26) k2 The reflection and transmission coefficients can be found by requiring both the wave function and its derivative to be continuous at the boundary x =0. − + Requiring ψ1(0 )=ψ2(0 ) gives 1 1 √ (1 + r)=√ t.
Load more

Recommended publications
  • Production Scientifique 2004-2007
    Production scientifique 2004-2007 Articles parus dans des revues internationales ou nationales avec comité de lecture 2004 • H. Bandulet, C. Labaune, K. Lewis and S. Depierreux, Thomson scattering study of the subharmonic decay of ion-acoustic waves driven by the Brillouin instability, Phys. Rev. Lett. 93, 035002 (2004) • S. Bastiani-Ceccotti, P. Audebert, V. Nagels-Silvert, J.P. Geindre, J.C. Gauthier, J.C. Adam, A. Héron and C. Chenais- Popovics, Time-resolved analysis of the x-ray emission of femtosecond-laser-produced plasmas in the 1.5-keV range, Appl. Phys. B 78, 905 (2004) • D. Batani, F. Strati, H. Stabile, M. Tomasini, G. Lucchini, A. Ravasio, M. Koenig, A. Benuzzi-Mounaix, H. Nishimura, Y. Ochi, J. Ullschmied, J. Skala, B. Kralikova, M. Pfeifer, C. Kadlec, T. Mocek, A. Prag, T. Hall, P. Milani, E. Barborini and P. Piseri, Hugoniot data for carbon at megabar pressures, Phys. Rev. Lett. 92, 065503 (2004) • A. Benuzzi-Mounaix, M. Koenig, G. Huse, B. Faral, N. Grandjouan, D. Batani, E. Henry, M. Tomasini, T. Hall and F. Guyot, Generation of a double shock driven by laser, Phys. Rev. E 70, 045401 (2004) • S. Bouquet, C. Stehlé, M. Koenig, J.P. Chièze, A. Benuzzi-Mounaix, D. Batani, S. Leygnac, X. Fleury, H. Merdji, C. Michaut, F. Thais, N. Grandjouan, T. Hall, E. Henry, V. Malka and J.P. Lafon, Observations of laser driven supercritical radiative shock precursors, Phys. Rev. Lett. 92, 225001 (2004) • P. Celliers, G. Collins, D. Hicks, M. Koenig, E. Henry, A. Benuzzi-Mounaix, D. Batani, D. Bradley, L. Da Silva, R.
    [Show full text]
  • Structuraland Magnetic Properties of Er3fe5-Xalxo12 Garnets
    CHAPTER 3 Structural and Magnetic Properties of Er3Fe5-xAlxO12 Garnets Ibrahim Bsoul1,a, Khaled Hawamdeh1,b, Sami H. Mahmood2,c 1Physics Department, Al al-Bayt University, Mafraq 13040, Jordan 2Physics Department, The University of Jordan, Amman 11942, Jordan [email protected], [email protected], [email protected] Abstract Er3Fe5-xAlxO12 (0.0 ≤ x ≤ 0.8) garnets were prepared by ball milling and sintering at 1300ºC. Rietveld refinement of the samples revealed a garnet structure with Ia3d symmetry. The lattice parameter, cell volume, X-ray density and magnetization of the prepared garnets decreased with the increase of Al content (x). The coercivity of the garnets increased with x, but remained generally low, being below 20 Oe. Low temperature magnetic measurements versus temperature indicated that the magnetization of x = 0.0 exhibited a compensation temperature at ˗186º C, however, x = 0.8 exhibited a minimum at a higher temperature of ˗134º C. Keywords Rare Earth Iron Garnet; Structural Characteristics; Magnetic Properties; Compensation Temperature; Thermomagnetic curves. Contents 1. Introduction 2. Experimental procedures 3. Results and discussion 3.1 XRD measurements 3.2 Magnetic measurements 3.3 Temperature dependence of the magnetic properties 3.4 Low temperature measurements 4. Conclusions References 1. INTRODUCTION Ferrimagnetic garnets exemplified by yttrium iron garnet (YIG) was discovery in 1956, and received considerable interest due to their low dielectric losses and remarkable performance in microwave devices and magnetic bubbles for digital memories [1, 2], in addition to their importance in the field of fundamental magnetism. The garnets have a cubic crystal structure 3+ 3+ 3+ 2− 3+ with space group Ia3d and chemical formula {R3 }c[Fe2 ]a(Fe3 )d O12 , where R is a trivalent rare-earth ion occupying dodecahedral (c) sites, and Fe3+ ions occupy octahedral [a- sublattice] and tetrahedral (d-sublattice) sites in the garnet lattice.
    [Show full text]
  • Pulsed Laser Deposition of High-Quality Μm-Thick YIG Films on YAG
    Pulsed laser deposition of high-quality μm-thick YIG films on YAG A. Sposito,1,* T. C. May-Smith,1 G. B. G. Stenning,2 P. A. J. de Groot,2 and R. W. Eason1 1Optoelectronics Research Centre, University of Southampton, SO17 1BJ, Southampton, United Kingdom 2Physics and Astronomy, University of Southampton, SO17 1BJ, Southampton, United Kingdom *[email protected] Abstract: We report the epitaxial growth of high-quality μm-thick yttrium iron garnet (YIG) films on yttrium aluminium garnet (YAG) substrates by pulsed laser deposition (PLD). The effects of substrate temperature and oxygen pressure on composition, crystallinity, optical transmission and ferromagnetic resonance (FMR) linewidth have been investigated. An FMR linewidth as low as 1.75 mT at 6 GHz was achieved by depositing YIG on YAG substrates with (100) orientation at a substrate temperature of ~1600 K and with oxygen pressure of ~1 Pa. ©2013 Optical Society of America OCIS codes: (160.3820) Magneto-optical materials; (310.1860) Deposition and fabrication. References and links 1. R. W. Eason, Pulsed Laser Deposition of Thin Films – Applications-led Growth of Functional Materials (Wiley Interscience, 2007). 2. N. A. Vainos, C. Grivas, C. Fotakis, R. W. Eason, A. A. Anderson, D. S. Gill, D. P. Shepherd, M. Jelinek, J. Lancok, and J. Sonsky, “Planar laser waveguides of Ti:sapphire, Nd:GGG and Nd:YAG grown by pulsed laser deposition,” Appl. Surf. Sci. 127-129, 514–519 (1998). 3. H. Dötsch, N. Bahlmann, O. Zhuromskyy, M. Hammer, L. Wilkens, R. Gerhardt, P. Hertel, and A. F. Popkov, “Applications of magneto-optical waveguides in integrated optics: review,” J.
    [Show full text]
  • A Tunable Magneto-Acoustic Oscillator with Low Phase Noise
    A tunable magneto-acoustic oscillator with low phase noise A. Litvinenko,1, ∗ R. Khymyn,2 V. Tyberkevych,3 V. Tikhonov,1 A. Slavin,3 and S. Nikitov1, 4, 5 1Laboratory of metamaterials, Saratov State University, 410012, Saratov, Russia. 2Department of Physics, University of Gothenburg, 412 96, Gothenburg, Sweden. 3Department of Physics, Oakland University, 48309, Rochester, Michigan, USA. 4Kotelnikov Institute of Radioengineering and Electronics of Russian Academy of Sciences, 125009, Moscow, Russia. 5Moscow Institute of Physics and Technology (National Research University), 141700, Dolgoprudny, Moscow Region, Russia. (Dated: November 17, 2020) A frequency-tunable low phase noise magneto-acoustic resonator is developed on the base of a parallel-plate straight-edge bilayer consisting of a yttrium-iron garnet (YIG) layer grown on a substrate of a gallium-gadolinium garnet(GGG). When a YIG/GGG sample forms an ideal parallel plate, it supports a series of high-quality-factor acoustic modes standing along the plate thickness. Due to the magnetostriction of the YIG layer the ferromagnetic resonance (FMR) mode of the YIG layer can strongly interact with the acoustic thickness modes of the YIG/GGG structure, when the modes' frequencies match. A particular acoustic thickness mode used for the resonance excitations of the hybrid magneto-acoustic oscillations in a YIG/GGG bilayer is chosen by the YIG layer FMR frequency, which can be tuned by the variation of the external bias magnetic field. A composite magneto-acoustic oscillator, which includes an FMR-based resonance pre-selector, is developed to guarantee satisfaction of the Barkhausen criteria for a single-acoustic-mode oscillation regime. The developed low phase noise composite magneto-acoustic oscillator can be tuned from 0.84 GHz to 1 GHz with an increment of about 4.8 MHz (frequency distance between the adjacent acoustic thickness modes in a YIG/GGG parallel plate), and demonstrates the phase noise of -116 dBc/Hz at the offset frequency of 10 KHz.
    [Show full text]
  • Phase and Frequency Locked Magnetrons for Srf Sources* M
    MOPC140 Proceedings of IPAC2011, San Sebastián, Spain PHASE AND FREQUENCY LOCKED MAGNETRONS FOR SRF SOURCES* M. Neubauer, R. Sah, A. Dudas, R. Johnson, M. A. C. Cummings, Muons, Inc. Batavia, IL, U.S.A. M. Popovic, A. Moretti, Fermilab, Batavia, IL, U.S.A Abstract As mentioned above, the yttrium aluminum garnet appeared to have some ideal characteristics, but since it Magnetrons are the lowest cost microwave high-power has low saturation magnetization, in the biasing field of sources in dollars/kW, with high efficiency (typically the magnetron these good characteristics may be lost. As greater than 85%). However, the frequency and phase a result, the materials chosen for testing are ones that have stability of magnetrons is inadequate when used as power a range of saturation magnetizations. sources for accelerators. Novel variable frequency cavity In an attempt to continue with the yttrium aluminum techniques have been developed which will be used to garnet as the material of choice, we have launched a phase and frequency lock magnetrons, allowing their use number of studies to find a way to shield the ferrite from for either individual cavities, or cavity strings. Ferrite or the main magnetic field. We have also started work on YIG (Yttrium Iron Garnet) materials will be attached in designing a control circuit for biasing the magnetic field. the regions of high magnetic field of radial-vaned, The remainder of the paper will describe the ferrite based π−mode structures of a selected ordinary magnetron to magnetron and the work related with these efforts. control the frequency of the magnetron.
    [Show full text]
  • Arxiv:2005.14133V2
    A First Principle Study on Magneto-Optical Effects in Ferromagnetic Semiconductors Y3Fe5O12 and Bi3Fe5O12 1 1,2, Wei-Kuo Li and Guang-Yu Guo ∗ 1Department of Physics and Center for Theoretical Physics, National Taiwan University, Taipei 10617, Taiwan 2Physics Division, National Center for Theoretical Sciences, Hsinchu 30013, Taiwan (Dated: August 4, 2020) The magneto-optical (MO) effects not only are a powerful probe of magnetism and electronic structure of magnetic solids but also have valuable applications in high-density data-storage tech- nology. Yttrium iron garnet (Y3Fe5O12) (YIG) and bismuth iron garnet (Bi3Fe5O12) (BIG) are two widely used magnetic semiconductors with significant magneto-optical effects. In particular, YIG has been routinely used as a spin current injector. In this paper, we present a thorough theoretical investigation on magnetism, electronic, optical and MO properties of YIG and BIG, based on the density functional theory with the generalized gradient approximation plus onsite Coulomb repul- sion. We find that YIG exhibits significant MO Kerr and Faraday effects in UV frequency range that are comparable to ferromagnetic iron. Strikingly, BIG shows gigantic MO effects in visible frequency region that are several times larger than YIG. We find that these distinctly different MO properties of YIG and BIG result from the fact that the magnitude of the calculated MO conduc- tivity (σxy) of BIG is one order of magnitude larger than that of YIG. Interestingly, the calculated band structures reveal that both valence and conduction bands across the semiconducting band gap in BIG are purely spin-down states, i.e., BIG is a single spin semiconductor.
    [Show full text]
  • The Elements.Pdf
    A Periodic Table of the Elements at Los Alamos National Laboratory Los Alamos National Laboratory's Chemistry Division Presents Periodic Table of the Elements A Resource for Elementary, Middle School, and High School Students Click an element for more information: Group** Period 1 18 IA VIIIA 1A 8A 1 2 13 14 15 16 17 2 1 H IIA IIIA IVA VA VIAVIIA He 1.008 2A 3A 4A 5A 6A 7A 4.003 3 4 5 6 7 8 9 10 2 Li Be B C N O F Ne 6.941 9.012 10.81 12.01 14.01 16.00 19.00 20.18 11 12 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 3 Na Mg IIIB IVB VB VIB VIIB ------- VIII IB IIB Al Si P S Cl Ar 22.99 24.31 3B 4B 5B 6B 7B ------- 1B 2B 26.98 28.09 30.97 32.07 35.45 39.95 ------- 8 ------- 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 39.10 40.08 44.96 47.88 50.94 52.00 54.94 55.85 58.47 58.69 63.55 65.39 69.72 72.59 74.92 78.96 79.90 83.80 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 5 Rb Sr Y Zr NbMo Tc Ru Rh PdAgCd In Sn Sb Te I Xe 85.47 87.62 88.91 91.22 92.91 95.94 (98) 101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.3 55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 6 Cs Ba La* Hf Ta W Re Os Ir Pt AuHg Tl Pb Bi Po At Rn 132.9 137.3 138.9 178.5 180.9 183.9 186.2 190.2 190.2 195.1 197.0 200.5 204.4 207.2 209.0 (210) (210) (222) 87 88 89 104 105 106 107 108 109 110 111 112 114 116 118 7 Fr Ra Ac~RfDb Sg Bh Hs Mt --- --- --- --- --- --- (223) (226) (227) (257) (260) (263) (262) (265) (266) () () () () () () http://pearl1.lanl.gov/periodic/ (1 of 3) [5/17/2001 4:06:20 PM] A Periodic Table of the Elements at Los Alamos National Laboratory 58 59 60 61 62 63 64 65 66 67 68 69 70 71 Lanthanide Series* Ce Pr NdPmSm Eu Gd TbDyHo Er TmYbLu 140.1 140.9 144.2 (147) 150.4 152.0 157.3 158.9 162.5 164.9 167.3 168.9 173.0 175.0 90 91 92 93 94 95 96 97 98 99 100 101 102 103 Actinide Series~ Th Pa U Np Pu AmCmBk Cf Es FmMdNo Lr 232.0 (231) (238) (237) (242) (243) (247) (247) (249) (254) (253) (256) (254) (257) ** Groups are noted by 3 notation conventions.
    [Show full text]
  • Photothermally Modulated Spatially Resolved FMR Detection of Walker Modes in Yttrium Iron Garnet Spheres O
    Photothermally modulated spatially resolved FMR detection of Walker modes in yttrium iron garnet spheres O. von Geisau, F. Rödelsperger, F. Schreiber, H. Benner, J. Pelzl To cite this version: O. von Geisau, F. Rödelsperger, F. Schreiber, H. Benner, J. Pelzl. Photothermally modulated spatially resolved FMR detection of Walker modes in yttrium iron garnet spheres. Journal de Physique IV Proceedings, EDP Sciences, 1994, 04 (C7), pp.C7-655-C7-658. 10.1051/jp4:19947155. jpa-00253214 HAL Id: jpa-00253214 https://hal.archives-ouvertes.fr/jpa-00253214 Submitted on 1 Jan 1994 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. JOURNAL DE PHYSIQUE IV Colloque C7, supplCment au Journal de Physique El, Volume 4, juillet 1994 Photothermally modulated spatially resolved FMR detection of Walker modes in yttrium iron garnet spheres 0. von Geisau, F. Rodelsperger*, F. Schreiber, H. Benner* and J. Pelzl Fakultatfur Physik und Astronomie, AG Festkorperspektroskopie, Ruhr-Universitat Bochum, 44780 Bochum, Germany * Institut fur FestkGrperphysik, Technische Hochchule Darmstadt, 64289 Darmstadt, Germany Abstract: The photothermally modulated (PM) ferromagnetic resonance (FMR) combines the high sensitivity of conventional FMR and spatial resolution. This technique has been applied to a single-crystalline yttrium iron garnet (YIG) sphere with a diameter of 2 mm.
    [Show full text]
  • New Ferrimagnetic Biocomposite Film Based in Collagen and Yttrium Iron Garnet
    eXPRESS Polymer Letters Vol.4, No.12 (2010) 790–797 Available online at www.expresspolymlett.com DOI: 10.3144/expresspolymlett.2010.95 New ferrimagnetic biocomposite film based in collagen and yttrium iron garnet S. D. Figueiro1, E. J. J. Mallmann2, J. C. Góes1, N. M. P. S. Ricardo3, J. C. Denardin4, A. S. B. Sombra1, P. B. A. Fechine2* 1Laboratory of Telecommunications and Materials Science and Engineering (LOCEM) – Physics Department, Federal University of Ceará – UFC, Campus do Pici, CP 12100, CEP 60451-970 Fortaleza – CE, Brazil 2Advanced Materials Chemistry Group (GQMAT) – Analytical and Physical-Chemistry Department, Federal University of Ceará – UFC, Campus do Pici, CP 12100, CEP 60451-970 Fortaleza – CE, Brazil 3Organic and Inorganic Chemistry Department, Federal University of Ceará – UFC, Campus do Pici, CP 12100, CEP 60451-970 Fortaleza – CE, Brazil 4Physics Department, Universidad de Santiago de Chile, USACH, Av. Ecuador 3493, Santiago, Chile Received 24 June 2010; accepted in revised form 25 August 2010 Abstract. In recent years a great interest in the study of the association of magnetic with biological material for bioapplica- tions has been observed in the literature. This work analyses the development of new magnetic biocomposite films from a magnetic ferrite and a biopolymer. Magnetic and dielectric properties of Y3Fe5O12 (YIG)/collagen composite films were studied as a function of the YIG concentration. This biocomposite was also characterized by Infrared Spectroscopy (IR), Thermal Analysis (DSC and TG) and scanning electron microspcopic (SEM) methods. The magnetization and dielectric measurements were performed at room temperature. The results demonstrated that ferrimagnetic garnet (YIG) and collagen (Col) can be used to obtain a homogeneous composite.
    [Show full text]
  • Investigation of Ca-Doped Yttrium Iron Garnet for Solid Oxide Fuel Cells
    University of Calgary PRISM: University of Calgary's Digital Repository Graduate Studies The Vault: Electronic Theses and Dissertations 2020-04-28 Investigation of Ca-doped Yttrium Iron Garnet for Solid Oxide Fuel Cells Zhang, Zheyu Zhang, Z. (2020). Investigation of Ca-doped Yttrium Iron Garnet for Solid Oxide Fuel Cells (Unpublished master's thesis). University of Calgary, Calgary, AB. http://hdl.handle.net/1880/111927 master thesis University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission. Downloaded from PRISM: https://prism.ucalgary.ca UNIVERSITY OF CALGARY Investigation of Ca-doped Yttrium Iron Garnet for Solid Oxide Fuel Cells by Zheyu Zhang A THESIS SUBMITTED TO THE FACULTY OF GRADUATE STUDIES IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE GRADUATE PROGRAM IN CHEMISTRY CALGARY, ALBERTA APRIL, 2020 © Zheyu Zhang 2020 Abstract Solid oxide fuel cells (SOFCs) are among the next-generation electrochemical energy conversion devices with higher energy efficiency. A major drawback hindering the mass commercialization of SOFCs is the slow oxygen reduction reaction kinetics at the cathode when the operating temperature is lowered from a high temperature (~1000 °C) to an intermediate temperature (500–750 °C). While many perovskite materials have been considered for use in novel SOFC cathodes, there remains a number of issues, such as large thermal expansion coefficient of Ba0.5Sr0.5Co0.8Fe0.2O3-δ due to the presence of Co and chemical instability under humidity and CO2- containing atmosphere of various perovskites.
    [Show full text]
  • Structural and Magnetic Properties of Ni-Doped Yttrium Iron Garnet Nanoparticles
    Structural and magnetic properties of Ni-doped yttrium iron garnet nanoparticles R. Peña-Garcia1, Y. Guerra2, F. E. P. Santos3, C. J. Sabino1 and E. Padrón-Hernández1,2 1Universidade Federal de Pernambuco, Departamento de Física, Recife-PE, Brazil 2Universidade Federal de Pernambuco, Pós Graduação em Ciência de Materiais, Recife-PE, Brazil 3Universidade Federal do Piauí, Departamento de Física, Teresina-PI, Brazil e-mail: [email protected] Abstract: We present a study about the structural and magnetic properties of Ni-doped yttrium iron garnet nanoparticles synthesized by sol-gel. X-ray diffractogram (XRD) indicate the replacement of iron by nickel, evidentiated in the increase of the lattice parameter from 12.3781 Å to 12.3961 Å with the increase in Ni concentration. Scanning Electron Microscopy (SEM) showed particles with a cylindrical format and aggregated, while the Energy Dispersive Spectroscopy (EDS) results corroborate the presence of Ni in YIG. The Fourier transform infrared and Raman spectroscopies confirmed the XRD results and indicated the substitution in the octahedral and tetrahedral sites. The value of saturation magnetization (Ms) for pure sample is 25.81 emu/g achieving the maximum of 26.37 emu/g for x = 0.01. The coercivity for pure sample is 55.72 Oe and increases to 66.45 Oe for x = 0.01. The magnetic measurements complement our results with the changes of the total moment and coercivity for different doping concentration. Keywords: Ni-doped YIG; magnetic properties; structural analysis; sol gel; Raman, FTIR. Introduction Yttrium iron garnet is the most important ferrimagnetic insulator for spintronic applications 3+ [1, 2].
    [Show full text]
  • Thermochromism in Yttrium Iron Garnet Compounds
    Thermochromism in Yttrium Iron Garnet Compounds Hélène Sérier-Brault, Lucile Thibault, Magalie Legrain, Philippe Deniard, Xavier Rocquefelte, Philippe Leone, Jean-Luc Perillon, Stéphanie Le Bris, Jean Waku, Stéphane Jobic To cite this version: Hélène Sérier-Brault, Lucile Thibault, Magalie Legrain, Philippe Deniard, Xavier Rocquefelte, et al.. Thermochromism in Yttrium Iron Garnet Compounds. Inorganic Chemistry, American Chemical Society, 2014, 53 (23), pp.12378-12383. 10.1021/ic501708b. hal-02572089 HAL Id: hal-02572089 https://hal.archives-ouvertes.fr/hal-02572089 Submitted on 13 May 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Thermochromism in yttrium iron garnet compounds Hélène Serier-Brault* ,†, Lucile Thibault †, Magalie Legrain †, Philippe Deniard †, Xavier Rocquefelte †, Philippe Leone †, Jean-Luc Perillon #, Stéphanie Le Bris #, Jean Waku #, Stéphane Jobic*,†. †Institut des Matériaux Jean Rouxel, Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes cedex, France #Tefal SA, Chemin des Granges, 74150 Rumilly, France ABSTRACT Polycrystalline yttrium iron garnets (Y 3Fe 5O12 ) were synthesized by solid-state reaction and characterized by X-ray diffraction, Mössbauer spectroscopy and UV-vis-NIR diffuse reflectance spectroscopy. The green color of the compounds have been assigned to the presence of a O2- Fe 3+ ligand-to-metal charge transfer together with d-d transitions, the absence of Fe 2+ in samples being verified with Mössbauer measurements.
    [Show full text]