DOCSLIB.ORG

UNITED STATES PATENT OFFICE METHOD of MAKING FNELY DVDED WOLATZED S LCA Richard Reik, Piedmont, and Alva C

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
UNITED STATES PATENT OFFICE METHOD of MAKING FNELY DVDED WOLATZED S LCA Richard Reik, Piedmont, and Alva C Patented Sept. 30, 1947 2428,178 UNITED STATES PATENT OFFICE METHOD OF MAKING FNELY DVDED WOLATZED S LCA Richard Reik, Piedmont, and Alva C. Byrns, Los Altos, Calif., assignors to The Permanente Metals Corporation, Oakland, Calif., a corpora tion of Delaware No Drawing. Application July 18, 1944, Serial No. 545,551 6 Claims, (C. 23-182) 2 This invention relates to finely divided amor the assumption slipped into the technical liter phous silicon dioxide that is in a condition of ature that silica is "volatile' in the presence of unusually high reactivity. This special kind of carbon at temperatures below 1600 C. by being silica, which shows valuable properties in a great reduced to silicon from which silica is again number of various applications is particularly formed by reoxidation (A. B. Searle, Refractory suited for use in the manufacture of refractory Materials, London, 1940, pp. 57/58 and 704). materials, Seeing that the boiling point of silica is at 2230 It is amongst the principal objects Of the inven C. and silicon boils even at 2600 C., the princi tion to prepare silica of an extraordinary degree ple underlying the above described empirical of fineness without having recourse to mechan 10 methods remained unexplained. ical trituration that requires special intensity or On the other hand it has been assumed for costly separation treatments to yield a material a long time that, analogously to the oxides of car anything similar to the Silica, resulting as a pri bon, silicon forms in addition to silicon dioxide mary product from the present process. Another a lower degree of oxidation of the formla SiO. eSSential object of the invention is to enable 5 According to the U. S. Patent No. 875,286 to amorphous Silica to be produced from naturally H. N. Potter, SiO is obtained by heating crystal Occurring Crystalline siliceous material. Both line silicon in the presence of oxygen under such these purposes are accomplished according to the conditions of oxygen supply and pressure as to present invention, without working cost being prevent the oxidation from progressing to the exceeded that are bearable in the manufacture of 20 stage of dioxide. For rendering the atmosphere a raw material which is intended for use in quan in which heating takes place adequately poor in tities like silica. To this end ordinary sorts of oxygen, Potter suggests to operate under re Silica, are caused to react with reducing agents at duced pressure or while diluting the normal at the relatively low temperature at which reduction mosphere with large quantities of an inert gas. to gaseous Silicon monoxide occurs, while con 25 Alternatively it has been proposed to prepare tinuously removing the SiO-gas from the reduc SiO by partial reduction of SiO2, for which pur ing Zone and Subjecting it to Oxidizing conditions pose different Ways have been chosen. to reform solid SiO2 therefrom which is then sep The first experiments were made in 188 with arated and collected. The dioxide appears in this fused silica while using carbon as the reducing manner in an extremely fine state of subdivision. 30 agent (American Chem. Journ, vol. 9, pp. 14/15). As early as in 1897 it has been discovered that In 1904. Potter succeeded in performing the car when fireclay is heated in the presence of car bothermic reduction. Without a melt by simply bon, part of the silica, is reduced and volatilized, heating a mixture of SiO2 and an amount of Some of the alkalis in the clay being volatilized at carbon that corresponds to the reaction the same time; subsequently the supposition was 35 made that volatilization occurs under oxidizing SiO2--C=SiO--CO conditions. No industrial application resulted to a temperature at which the monoxide volatil from these observations until in 1912, the British izes. Another investigator, Frank G. Tone, dis Thomson-Houston Co. disclosed a method of pro closed in the U. S. patent No. 993,913 a similar ducing refractory materials by highly heating 40 method of partial reduction of SiO2 by means of mixtures of silica and carbon that contain a me carbon, while leaving the question undecided tallic compound intended to yield the respective Whether the product obtained by condensation metal by reduction, and by collecting the "sub from the gaseous products of combustion leaving limate.' A treatment of Such kind of a mixture the reduction furnace, was a lower oxide of sili of silica, carbon and an aluminum silicate, with 45 con or a mixture of silica and amorphous silicon. or without one part of manganese oxide, is re - According to Tone the silica to carbon ratio in ported to result in a felted material of low thermal the furnace feed may conform to the reaction conductivity. A similar process consists in heat ing a mixture of silica, carbon and rutile in an SiO2--2C=Si--2CO electric furnace under reducing conditions and 50 or be even lower in silica and higher in carbon, collecting the sublimate of flaky, laminated respectively; but Tone adds that it is much bet ter to employ mixtures higher in silica since Structure that contains silicon, carbon, titanium Such mixtures yield the desired product in greater and oxygen (British specifications Nos. 25,370, abundance. 1912, and 29,389, 1912). Out of these disclosures 55 A second method, proposed by Potter in his 2428,178 4. 3 monoxide which is disengaged as a gas at temper specification No. 875.675, consists in performing atures far below the boiling point of silicon, and the partial reduction of SiO2 with the aid of readily reforms SiO2 on contact with air. How silico according to the equation ever, this sequence of reactions was heretofore SiO2--Sis2SiO. turned to account only for the production of coS netics such as dentifrice and face powder be for instance by heating an approximately com cause of yielding a finely divided powder of posed mixture of Si and SiO2 above the resistor of white color. Thereby it did not come to light an electric furnace of the arc type in an in that silicon dioxide directly produced by the way different atmosphere. 0. of gaseous SiO without intermediately isolating Finally according to R. Flusin (Ind. chimique solid SiO by condensation shows the character 9, 391) silicon carbide may be used instead of and function of a chemical of extremely high re carbon for the reduction by means of the re activity that is particularly valuable for the man action ufacture of refractory materials; nor was it SiOa--SiC=SiO--Si-CO recognized that this method offers the possibility Of whatever kind the reducing agent may be, s of preparing amorphous silica from naturally Oc the silicon monoxide is liberated in the state of curring crystalline raw materials without oppres brown-colored vapors which have to be condensed sive rise of the manufacturing expenses. quickly because otherwise decomposition takes The development of these discoveries of more place according to the equation 2SiO=SiO2--Si generai import may have been impeded by the (Ulmann, Enzyklopaedie der technis chen 920 fact that it was an open question whether the Chemie, 2nd ed., 1932, vol. 9, p. 505). The silicon product resulting from the partial reduction of monoxide depositing on condensation is reported SiO2 and Subsequent oxidation of the vapor to be in the form of an extremely finely divided evolved was actually a distinct substance of the powder or to appear at least principally in that formula SiO or rather a mixture of silica and form while a smaller portion is in the vitreous 25 silicon showing the composition of SiO. As al State. ready pointed out, Frank G. Tone left this ques Powders of such kind are meant for use as tion undecided in 1907; this was still the state of body for oil paints and for thermal and electrical the matter in 1941, though K. F. Bonhoeffer had insulation purposes, moreover as abrasive or pol in the meantime succeeded in establishing, by ex ishing powders (Ullmann, loc. cit.). Frank G. 80 amining the absorption spectra, that in the prod Tone mentions in the first place the use of his lucts formed by reduction of silicon dioxide with products as reducing agents. carbon actually the compound SiO is existent Apart therefrom, Potter suggests to utilize the in the gaseous state (Zeitschrift fuer physikalische finely subdivided silicon monoxide powder result Chemie, vol. 131/132, 1927 to 1928, p. 363). Zintil ing from partial reduction of SiO2 for converting 35 reports in 1940 (Zeitschrift fuer anorganische und it into silicon dioxide of equal fineness by oxida allegemeine Chemie, 245, 1 to 7) that quick con tion. Potter states that there are various ways densation of the vapor evolved in the vapor space of doing this, one of which consists in blowing results in the formation of an exceedingly light, a dust of silicon monoxide through a heated finely divided powder, but adds that the ques chamber in which it is oxidized by reaction with 40 tion whether the said powder consists of the an oxidizing gas (specification No. 886,637). A chemical individual SiO or a mixture of Si and second method consists in blowing an oxidizing SiO2 in correspondent proportions could not have gas through a furnace during the progress of re been decided until then. Likewise, H. N. Baumann action which, per se, would liberate silicon mon 45 stated in 1941 in Transactions of the Electro oxide (specification No. 875,674). Still another chemical Society, vol. 80, 95, 1941, that the ex method, that is disclosed in specification No. istence of silicon monoxide has been reported at 908,131 consists in burning the powder of silicon different times, but it has remained doubtful monoxide in the state of suspension in an oxidiz whether this suboxide is a definite compound.
Load more

Recommended publications
  • Directed Gas Phase Formation of Silicon Dioxide and Implications for the Formation of Interstellar Silicates
    ARTICLE DOI: 10.1038/s41467-018-03172-5 OPEN Directed gas phase formation of silicon dioxide and implications for the formation of interstellar silicates Tao Yang 1,2, Aaron M. Thomas1, Beni B. Dangi1,3, Ralf I. Kaiser 1, Alexander M. Mebel 4 & Tom J. Millar 5 1234567890():,; Interstellar silicates play a key role in star formation and in the origin of solar systems, but their synthetic routes have remained largely elusive so far. Here we demonstrate in a combined crossed molecular beam and computational study that silicon dioxide (SiO2) along with silicon monoxide (SiO) can be synthesized via the reaction of the silylidyne radical (SiH) with molecular oxygen (O2) under single collision conditions. This mechanism may provide a low-temperature path—in addition to high-temperature routes to silicon oxides in circum- stellar envelopes—possibly enabling the formation and growth of silicates in the interstellar medium necessary to offset the fast silicate destruction. 1 Department of Chemistry, University of Hawai’iatMānoa, Honolulu, HI 96822, USA. 2 State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200062, China. 3 Department of Chemistry, Florida Agricultural and Mechanical University, Tallahassee, FL 32307, USA. 4 Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA. 5 Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, Belfast, BT7 1NN, UK. Correspondence and requests for materials should be addressed to R.I.K. (email: [email protected]) or to A.M.M. (email: mebela@fiu.edu) or to T.J.M. (email: [email protected]) NATURE COMMUNICATIONS | (2018) 9:774 | DOI: 10.1038/s41467-018-03172-5 | www.nature.com/naturecommunications 1 ARTICLE NATURE COMMUNICATIONS | DOI: 10.1038/s41467-018-03172-5 — 28 + 28 + he origin of interstellar silicate grains nanoparticles ( SiO2 ), and 44 ( SiO ).
    [Show full text]
  • Ground State Structure and Physical Properties of Silicon Monoxide Sheet T ⁎ Yanyan Chen, Yupeng Shen, Yiheng Shen, Xiaoyin Li, Yaguang Guo, Qian Wang
    Applied Surface Science 527 (2020) 146759 Contents lists available at ScienceDirect Applied Surface Science journal homepage: www.elsevier.com/locate/apsusc Full Length Article Ground state structure and physical properties of silicon monoxide sheet T ⁎ Yanyan Chen, Yupeng Shen, Yiheng Shen, Xiaoyin Li, Yaguang Guo, Qian Wang Center for Applied Physics and Technology, Department of Materials Science and Engineering, HEDPS, BKL-MEMD, College of Engineering, Peking University, Beijing 100871, China ARTICLE INFO ABSTRACT Keywords: Two-dimensional (2D) silicon oxides have received considerable attention in recent years because of their ex- 2D silicon monoxide (SiO) cellent compatibility with the well-developed Si-based semiconductor technology. Though the ground state Global structure search structure of 2D silicon dioxide (SiO2) was identified many years ago, the corresponding study of 2D silicon Physical properties monoxide (SiO) has not yet been reported. Herein, using global structure search method combined with density Ground state structure functional theory and Boltzmann transport theory, we find the ground state structure of 2D SiO, named Orth-SiO, and systematically study its physical properties. Orth-SiO is found to be thermally, dynamically and mechani- cally stable, and possesses a direct band gap of 1.52 eV, which is much smaller as compared to that of α-2D silica (7.31 eV). Moreover, it exhibits significant anisotropies in mechanical properties and optical adsorption due to its exceptional atomic configuration. The lattice thermal conductivity of Orth-SiO is 80.45 and 33.79 W/mK along the x and y directions at room temperature, respectively, much higher than that of many Si-based ma- − − terials due to its weak anharmonicity.
    [Show full text]
  • Silicon Monoxide at 1 Atm and Elevated Pressures: Crystalline Or Amorphous? Khalid Alkaabi,† Dasari L
    Article pubs.acs.org/JACS Silicon Monoxide at 1 atm and Elevated Pressures: Crystalline or Amorphous? Khalid AlKaabi,† Dasari L. V. K. Prasad,†,# Peter Kroll,§ N. W. Ashcroft,‡ and Roald Hoffmann*,† † Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States § Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States ‡ Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, United States *S Supporting Information ABSTRACT: The absence of a crystalline SiO phase under ordinary conditions is an anomaly in the sequence of group 14 monoxides. We explore theoretically ordered ground-state and amorphous structures for SiO at P = 1 atm, and crystalline phases also at pressures up to 200 GPa. Several competitive ground-state P = 1 atm structures are found, perforce with Si−Si bonds, and possessing Si−O−Si bridges similar to those in silica (SiO2) polymorphs. The most stable of these static structures is enthalpically just a little more stable than a calculated random bond model of amorphous SiO. In that model we find no segregation into regions of amorphous Si and amorphous SiO2. The P = 1 atm structures are all semiconducting. As the pressure is increased, intriguing new crystalline structures evolve, incorporating Si triangular nets or strips and stishovite-like regions. A heat of formation of crystalline SiO is computed; it is found to be the most → negative of all the group 14 monoxides. Yet, given the stability of SiO2, the disproportionation 2SiO(s) Si(s)+SiO2(s) is exothermic, falling right into the series of group 14 monoxides, and ranging from a highly negative ΔH of disproportionation for CO to highly positive for PbO.
    [Show full text]
  • Silicon Monoxide - Properties and Evaporation Techniques
    Silicon Monoxide - Properties and Evaporation Techniques Distributed by the RD Mathis Company 2840 Gundry Ave., Signal Hill, CA 90755 Phone (562) 426-7049 Fax (562) 595-0907 RDMathis.com [email protected] Abstract Silicon monoxide, SiO, is volatile at temperatures above 1100°C and can be readily vacuum deposited to form amorphous films with small grain size, high dielectric strength and good adhesion to glass. The films are not hygroscopic, are chemically stable at low oxygen pressures and temperatures below 200°C, and show good abrasion resistance. It has therefore gained wide acceptance as a thin film material for such diverse applications as: electrically insulating layers, capacitor dielectrics, optical films, protective overcoats for front surface mirrors and microcircuits, intermediate layers to increase the adhesion of other materials, and buffer layers to reduce chemical interactions between other materials. The detailed optical and electrical properties of silicon monoxide films depend strongly on the rate of evaporation of the material, type of source used and residual atmosphere in the vacuum chamber. With a reasonable amount of care, however, reproducible films of highly desirable characteristics can be obtained. Introduction Of all the simple chemical compounds (i.e. sodium fluoride, lithium fluoride, boron oxide, cryolite, zinc sulphide, bismuth oxide and magnesium fluoride) that have been studied by the authors and other workers in the thin film field, silicon monoxide has the most suitable physical properties for a wide variety of uses. Good films of this material are readily prepared in vacuum systems capable of producing only modest pressures (2x10-6torr or better) on a reproducible basis.
    [Show full text]
  • Chemical Names and CAS Numbers Final
    Chemical Abstract Chemical Formula Chemical Name Service (CAS) Number C3H8O 1‐propanol C4H7BrO2 2‐bromobutyric acid 80‐58‐0 GeH3COOH 2‐germaacetic acid C4H10 2‐methylpropane 75‐28‐5 C3H8O 2‐propanol 67‐63‐0 C6H10O3 4‐acetylbutyric acid 448671 C4H7BrO2 4‐bromobutyric acid 2623‐87‐2 CH3CHO acetaldehyde CH3CONH2 acetamide C8H9NO2 acetaminophen 103‐90‐2 − C2H3O2 acetate ion − CH3COO acetate ion C2H4O2 acetic acid 64‐19‐7 CH3COOH acetic acid (CH3)2CO acetone CH3COCl acetyl chloride C2H2 acetylene 74‐86‐2 HCCH acetylene C9H8O4 acetylsalicylic acid 50‐78‐2 H2C(CH)CN acrylonitrile C3H7NO2 Ala C3H7NO2 alanine 56‐41‐7 NaAlSi3O3 albite AlSb aluminium antimonide 25152‐52‐7 AlAs aluminium arsenide 22831‐42‐1 AlBO2 aluminium borate 61279‐70‐7 AlBO aluminium boron oxide 12041‐48‐4 AlBr3 aluminium bromide 7727‐15‐3 AlBr3•6H2O aluminium bromide hexahydrate 2149397 AlCl4Cs aluminium caesium tetrachloride 17992‐03‐9 AlCl3 aluminium chloride (anhydrous) 7446‐70‐0 AlCl3•6H2O aluminium chloride hexahydrate 7784‐13‐6 AlClO aluminium chloride oxide 13596‐11‐7 AlB2 aluminium diboride 12041‐50‐8 AlF2 aluminium difluoride 13569‐23‐8 AlF2O aluminium difluoride oxide 38344‐66‐0 AlB12 aluminium dodecaboride 12041‐54‐2 Al2F6 aluminium fluoride 17949‐86‐9 AlF3 aluminium fluoride 7784‐18‐1 Al(CHO2)3 aluminium formate 7360‐53‐4 1 of 75 Chemical Abstract Chemical Formula Chemical Name Service (CAS) Number Al(OH)3 aluminium hydroxide 21645‐51‐2 Al2I6 aluminium iodide 18898‐35‐6 AlI3 aluminium iodide 7784‐23‐8 AlBr aluminium monobromide 22359‐97‐3 AlCl aluminium monochloride
    [Show full text]
  • Silicon Production Using Long Flaming Coal and Improvement of Its Quality Indicators
    A. D. MEKHTIEV, M. J. TOLYMBEKOV, A. V. KIM, ZH. D. ZHOLDUBAEVA, ISSN 0543-5846 D. K. ISSIN, A. Z. ISSAGULOV, B. D. ISSIN METABK 53(4) 563-566 (2014) UDC – UDK 669.782:669.046:669.041:662.642=111 SILICON PRODUCTION USING LONG FLAMING COAL AND IMPROVEMENT OF ITS QUALITY INDICATORS Received – Primljeno: 2013-07-25 Accepted – Prihvaćeno: 2014-03-30 Preliminary Note – Prethodno priopćenje The object of this study is to explore possibility of metallothermic producing of crystalline silicon using various types of carbon reducing agents as a reducing agent. The experience of existing enterprises shows that one of the best carbon reducing agents qualifying silicon electric melting technology is charcoal. On the other hand, charcoal has a number of disadvantages, such as its scarcity, high cost and low mechanical strength. Experimental melts has shown the principal possibility of producing the crystalline silicon that meets the requirements of quartz standard using low ash special coke and long-flame coal as reducing agents. Key words: silicon, metalthermie, furnace charge, reducer, coke, electric melting, concentrate, quartzite, technology, metallurgy, iron, basicity, oxide, slag, ferroalloy INTRODUCTION small amount of slag – 2 - 3 % of the melted alloy mass General patterns of silica recovery using carbon can complicates the process and affects the quality of silicon, be determined by the thermodynamic analysis of Si-OC that’s why the main requirement to quartz, used as raw system. material for the melting of crystalline silicon, is its purity The main summary reactions associated with silicon (it shouldn’t contain such impurities as oxides of alumi- production, are: num, iron, calcium, titanium, and other elements).
    [Show full text]
  • Solid-State Reduction of Silica Nanoparticles Via Oxygen Abstraction from Sio4 Units by Polyolefins Under Mechanical Stressing
    RSC Advances View Article Online PAPER View Journal | View Issue Solid-state reduction of silica nanoparticles via oxygen abstraction from SiO units by polyolefins Cite this: RSC Adv.,2018,8, 36338 4 under mechanical stressing† Mamoru Senna, *ab Hirotaka Noda, b Yunzi Xin, b Hiroki Hasegawa, b Chika Takai, b Takashi Shirai *b and Masayoshi Fuji b Metal oxides with an oxidation number lower than the highest often exhibit attractive functional properties. However, conventional chemical or thermal reduction of the stable oxides is often laborious and cannot be stopped at an appropriate level of reduction. Therefore, we here try to explore non-conventional reduction processes in a solid-state without external heating. Unique features of reduction processes of SiO2 toward suboxides, SiOx (1 # x < 2), were made possible by milling fumed silica nanoparticles with polyolefins (POL), i.e., polypropylene (PP) or polyethylene (PE) and a fluorine-containing one, polyvinylidene difluoride (PVDF). We mainly examined the electronic and coordination states of Si by Si2p XPS spectra and 29Si MAS NMR, Creative Commons Attribution-NonCommercial 3.0 Unported Licence. respectively. They significantly differ from a similar commercial product obtained via a thermal route. 29 Judging from the chemical shift of Si MAS NMR as a criterion of the degree of reduction of SiO2, the function of POL as a reductant is in the order PP z PE > PVDF. Since the present solid-state reaction is free from the formation of unstable gaseous SiO as an intermediate, the products are free from the Si component in a Q0 state close to that of metallic Si.
    [Show full text]
  • Reduction of Quartz to Silicon Monoxide by Methane-Hydrogen Mixtures
    University of Wollongong Research Online Faculty of Engineering and Information Faculty of Engineering and Information Sciences - Papers: Part A Sciences 1-1-2016 Reduction of quartz to silicon monoxide by methane-hydrogen mixtures Xiang Li University of Wollongong, [email protected] Guangqing Zhang University of Wollongong, [email protected] Ragnar Tronstad Elkem AS, [email protected] Oleg Ostrovski University of New South Wales, [email protected] Follow this and additional works at: https://ro.uow.edu.au/eispapers Part of the Engineering Commons, and the Science and Technology Studies Commons Recommended Citation Li, Xiang; Zhang, Guangqing; Tronstad, Ragnar; and Ostrovski, Oleg, "Reduction of quartz to silicon monoxide by methane-hydrogen mixtures" (2016). Faculty of Engineering and Information Sciences - Papers: Part A. 5882. https://ro.uow.edu.au/eispapers/5882 Research Online is the open access institutional repository for the University of Wollongong. For further information contact the UOW Library: [email protected] Reduction of quartz to silicon monoxide by methane-hydrogen mixtures Abstract The reduction of quartz was studied isothermally in a fluidized bed reactor using continuously flowing methane-hydrogen gas mixture in the temperature range from 1623 K to 1773 K (1350 °C to 1500 °C). The CO content in the off-gas was measured online using an infrared gas analyzer. The main phases of the reduced samples identified yb XRD analysis were quartz and cristobalite. Significant weight loss in the reduction process indicated that the reduction products were SiO and CO. Reduction of SiO2 to SiO by methane starts with adsorption and dissociation of CH4 on the silica surface.
    [Show full text]
  • Silicon Monoxide Patinal®
    Product Information Silicon Monoxide Patinal® GENERAL INFORMATION SiO is a commonly used material for a wide variety of applications with the emphasis on IR multilayer coatings and adhesion promotion. SiO sublimes and should preferably be evaporated from resistance heated boats. AREAS OF APPLICATION • Multilayer coatings especially for the IR, but also the VIS range • Adhesion promoter (VIS, NIR) • Electronics: dielectric, insulating and protective layers • Design: iridescent coatings, colored metallically reflecting coatings e.g. on sun glasses • Web coating: barrier layers on polymer films THIN FILM PROPERTIES The optical properties of layers made from SiO depend very much on the evaporation conditions (reactive oxygen, ion assistance) and the resulting oxidation state and layer structure. SiO Si2O3 SiO2 Range of Transparency 800 – 9000 nm 380 – 9000 nm 190 – 9000 nm 1.8 (1 µm), 1.6 1.55 (500 nm) 1.46 (550 nm) Refractive index (7 µm) Dielectric constant 5 – 9 1.55 1.46 Dielectric loss (tan δ) 0.02 – 0.16 0.001 – 0.02 0.6 – 1⋅10-3 Resistivity 107 – 1012 Ω cm 1012 – 1016 Ω cm 1017 Ω cm Color Yellow / brown Colorless Colorless Status: 04 / 2019, Page 1 of 4 EMD Performance Materials* One International Plaza Suite 300 / Philadelphia, PA / 19113 USA +888 367 3275 / [email protected] / patinal.com * EMD Performance Materials is a business of Merck KGaA, Darmstadt, Germany NOTES FOR EVAPORATION Evaporator source Resistance heater thermal evaporation Electron beam evaporator Boat / Liner Molybdenum, tungsten, tantalum Evaporation temperature 1200 – 1600 °C Deposition rate ∼ 0.8 nm/s (SiO), ∼ 0.4 nm/s (Si 2O3) -5 -4 Oxygen partial pressure < 2 ⋅10 mbar (SiO), 1 - 3⋅10 mbar (Si 2O3) QCR-settings Density 2.13 g/cm³, Z-ratio 0.870 PRODUCTS Product Code Description Purity * Dimensions 1.07716 Silicon Monoxide Granules Patinal ≥ 99.99 % (4N) Granules, about 2 – 4 mm 1.10553 Silicon Monoxide Granules Patinal ≥ 99.99 % (4N) Granules, about 4 – 8 mm * The purity values are based on the specified trace metals.
    [Show full text]
  • Mechanism of Molecule Migration of Carbon and Silicon Monoxides in Silicon Carbide Crystal S.A
    Materials Physics and Mechanics 42 (2019) 178-182 Received: December 11, 2018 MECHANISM OF MOLECULE MIGRATION OF CARBON AND SILICON MONOXIDES IN SILICON CARBIDE CRYSTAL S.A. Kukushkin1,2*, A.V. Osipov3, E.V. Osipova1 1Institute of Problems of Mechanical Engineering, Russian Academy of Sciences, St. Petersburg, Russia 2Peter the Great Saint Petersburg State Polytechnic University, St. Petersburg, Russia 3ITMO University, St. Petersburg, Russia *e-mail: [email protected] Abstract. The main processes occurring during the migration of molecules of carbon monoxide CO and silicon monoxide SiO gases through a layer of monocrystalline silicon carbide SiC of a cubic polytype have been described by the ab initio methods. This problem arises when a single-crystal SiC layer is grown by the method of coordinated substitution of atoms due to the chemical reaction of a crystalline silicon substrate with the CO gas. The reaction products are epitaxial SiC layer and SiO gas. It has been shown that CO and SiO molecules decompose into separate atoms in the SiC crystal. The Oxygen atoms migrate through interstices only in the [110] direction (activation energy is 2.6 eV). The Si and C atoms transit by the vacancy mechanism in the corresponding SiC sublattices with activation energies of 3.6 eV and 3.9 eV respectively (and also only in the [110] direction). Keywords: silicon carbide, epitaxy, diffusion, ab initio modelling 1. Introduction During the growth of the epitaxial film of silicon carbide (SiC) from a silicon (Si) crystal by the method of coordinated substitution of atoms due to the chemical reaction [1] 2Si (crystal) + CO (gas) = SiC (crystal) + SiO (gas) ↑ , (1) the transport of carbon monoxide (CO) reagent gas and silicon monoxide (SiO) reaction product gas through the SiC layer plays a key role in determining the growth rate of SiC.
    [Show full text]
  • Formation and Destruction of Silicon Monoxide in SN 1987A
    Formation and Destruction of Silicon Monoxide in SN 1987A The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Liu, Weihong, and A. Dalgarno. 1996. “Formation and Destruction of Silicon Monoxide in SN 1987A.” The Astrophysical Journal 471 (1): 480–84. https://doi.org/10.1086/177982. Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:41397475 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Other Posted Material, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#LAA THE ASTROPHYSICAL JOURNAL, 471:480È484, 1996 November 1 ( 1996. The American Astronomical Society. All rights reserved. Printed in U.S.A. FORMATION AND DESTRUCTION OF SILICON MONOXIDE IN SN 1987A WEIHONGLIU AND A. DALGARNO Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 Received 1996 March 21; accepted 1996 May 31 ABSTRACT We present a new chemistry model for the silicon monoxide molecules in SN 1987A. It incorporates an enhanced rate of formation by radiative association and an enhanced rate of destruction through charge transfer between SiO and Ar` and Ne`, which is more efficient than the energetic electron impact ionization and dissociation in a previous model. The conclusion is unchanged that the 10~4È10~3 M_ of SiO observed in SN 1987A can be produced by chemistry models in which there is no microscopic mixing of helium into the silicon-oxygen region of the ejecta. Subject headings: molecular processes È supernovae: individual (SN 1987A) 1.
    [Show full text]
  • Silicon Dioxide Films, Heated (R
    Volume 20 / Issue 1 March, 2010 In this quarter’s CMN, we discuss the depo- rating silicon monoxide from a resistance- erties and the advantages of mixtures of oxide sition of all-important Silicon dioxide films, heated (R. H.) or E-beam-heated source from compounds and mixtures of fluoride com- including the never-ending quest to control which the vapor is created by sublimation. pounds are frequently discussed in CMN. mechanical stress in thin films, and the cre- An oxygen background pressure high in the Unfortunately, any additive to silicon diox- ation of colored reflection films for decora- 10 e-05 Torr range is required to produce ide will result in increasing its film index, how- tive functions. oxidized films. This reactive method has been ever, the advantage to be gained is reduced shown to produce films with lower absorp- intrinsic stress. Small percentages of alumi- tion and better vapor stream distribution than num oxide have been co-sputtered or co- Silicon Dioxide Films is produced by evaporation from fused silica evaporated with silicon dioxide to reduce source materials. Depositing SiO2 by R.H. stress. Silicon Dioxide, SiO2, is the common low- from a SiO baffle box provides a consistent index layer material in oxide-based optical vapor stream because there is no surface to coatings for the spectral range ~250 nm to erode as there is when using E-beam evapo- Processes involving high energy deposition ~2500 nm. It is paired with high- and mid- ration. Ion assisted (IAD) or plasma-ion techniques such as IAD, PIAD, or sputtering index layers such as TiO , Ta O , Nb O , assisted (PIAD) processes are added to E- that produce high packing densities also in- 2 2 5 2 5 crease compressive stress.
    [Show full text]