Scholars' Mine Masters Theses Student Theses and Dissertations 1949 The lithium tungsten bronzes Shun Sheng Hsu Follow this and additional works at: https://scholarsmine.mst.edu/masters_theses Part of the Metallurgy Commons Department: Recommended Citation Hsu, Shun Sheng, "The lithium tungsten bronzes" (1949). Masters Theses. 4869. https://scholarsmine.mst.edu/masters_theses/4869 This thesis is brought to you by Scholars' Mine, a service of the Missouri S&T Library and Learning Resources. This work is protected by U. S. Copyright Law. Unauthorized use including reproduction for redistribution requires the permission of the copyright holder. For more information, please contact [email protected]. MSM HISTORICAL COLLECTJO/f THE LITHIUM TUNGSTEN BRONZES By SHUN SHENG HSU --------- A THESIS submitted to the faculty of the SCHOOL OF MINES AND l'J1ET.ALLURGY OF THE UNIVERSITY OF MISSOURI in partial fulfillment of the work required for the Degree of MASTER OF SCIENCE IN METALLURGICAL ENGINEERING Rolla, Missouri 1949 MSM HISTORICAl COLLECTION Approved by______ ~~~·--~ __. __ (31,__ ~---~-~-~-~_,_·~--------------- Rese ch professor of Metallurgy ACKI~OWLEDGEMENT The author wishes to express his sincere apprec- iation to Dr. M. E. Straumanis, Research professor of lv'Iets.llurgy, Missouri School of Mines and Metallurgy, Rolls., Missouri for his many valuable suggestions which were g·iven during the course of this investigation; to Dr. A. w. Scblechten, Chairman of the Department of Metallurgy, Missouri School of Mines and Metall~rgy for the correction o:f the manuscript; and to Dr • . D. s. Eppelshe·imer, professor o:f Metallurgical Engineering, Missouri School o:f Mines and Metallurgy for the permis­ sion to use his x-ray machine :for diffraction work. iii CONTENT Page Acltrl owledg amen t . ii List of Illustra.tions •..•••••.......•..•.... iv List of Tables- • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • v Ill tr OO.u c t ion • . • • . • • • • . • • • • • . • . • . • • • . • • • 1 R'eview of Literature • • . • • • . • • . • • • . • . • . 3 The: Preparation of Lithium '!Ungsten Bronzes • 6 '!he CJ',hemioal and Other Properties ot Lithium 'nlngs·ten Bronzes • • • . • . • • • 16 The Structure of Lithium '!Ungsten Bronzes •.• 19 ~e Solid Solutions of L1W03 and Wo 3 Serie~t. • 34 Summ:ary- . • • • . • • • • • • • . • . • • • • . • • . 4S Bibliograp ey • . • • • . • . • . • . 5) Vita • . • . • . • . • . · . · . · . · • !>2 iv LIST OF ILLUSTRATIONS Figure page ~. The Schematic Arrangement o:f the Heat- ing System • • • • • • • • • • • • • • 7 2. Comparison o:f the X-ray -Diffra ction patterns of' Li-W-Bronze a nd Na-w­ Bronze (Co-radiation) • • • • • • • • • • ~~ 3. ~be Schematic Arrangement :for the Reaction of Tungstic Oxide and Lith- i~ . Iod~e •••••••••••••• . .. ~8 4. The Graphic Method for Indexing X-ray Powder Photographs of Cubic Crystals Using cu-radi a ti on • • • • • • • • . • • • • 22 5. The Graphic Method f'or Indexing X-ray Powder photographs of' Cubic Crys- tals Using Co-radiation ••••••• • • 23 6. ~olarization Factor versus Bragg Ang~e e. .• .• . • • . • • • 26 '1. Absoi};>tion Factor versus Bragg Angle e • • • • • • • • • • • • • • • • • 29 a. The Crystal Structure of' Ideal LiWO 31 3 • • •• The X-ray powder Photographs of' Sane Li-W-Bronze Sample with Cu and Oo Radiations • • • • • • • · • • • • • • • • • 41 10. X-ray Powder Photographs Showing the Lattice· Changes o:f Li-W-Bronzes w1 th Increa sing Amount of' WO in Solid Solution. • • • • • • ~ • • •••• • • • 11.. The Lattice Constant Changes versus the WO Content in the Li-W-Bronzes. 3 • •• 12. The x-ray Powder :Photograph of' the Sample Contains 80% Wo • Showing The Forrm. tion o:f a. New3 Phase. (Co-radiation) ••••••••••• • • • 47 13. • The. X-ray Powder photograph o:f pure WO (Oo-r~diation) ••••••••• 3 • • • v LIST OF TAB IE S Table page I. 2 Values of the Diffraction Lines on F. 60 a. nd F. l. 0 7 • • • • • • • • • • • • 21 II. The Theoretical and Observed Inten­ sities of Ideal ~thium Metatungstate Crystals • ..• .• :• :• • • • • • • • • • • • 30 Ill. Example o:f Fil.m Measurement and OaJ.cuJ.s.tion • • . • • • • • • • • • • • 36 IV. The 2d Values and the Cor respond- ing Intensi ties of the More Intense Reflections :from Li-W-Bronze Crystal. • • • • • • • • • • • • • • • • 40 v. The wave Lengths ·of K Radiations for ~he Common Target ilements Using for -Diffraction • • • • • • ;• .. ;• 40 VI. The Col.or and Lattice Changes of tl:e LiW0 W0 Se rie a • • • • • • • 3 3 44 1 INTRODUCTION The "tungsten bronzes" are a series of anionic sub- stitutional solid solutions of alkali or alkaline earth metal metatungstates and tungstic oxide. They are nei- ther alloys or intermetallic compounds, the term "tung­ sten bronzes" was adopted because of their remarkable metallic properties -- e.g., high electrical conductiv­ ity, metallic luster on the crystal, and high specific gravity. Also owing to their intense and vivid colors and chemical inactivity it was possible to use them in the paint industry as a substitute :for the so-called "bronze powders", the latter term is applied to the fine- .... ly divided metal powders, such as aluminum, copper, brass, and bronze powders. The paint made of these tungsten · bronzes with some binding materials are used to protect metal surfaces ~nd for ornamental purpose. The properties and structure of some of those tung­ sten bronzes are still unknown; in the last two decades, no published investigation about lithium tungsten bron­ (1) zes has been made. The present work is intended to find out the struc­ ture and some other properties of the lithium tungsten bronzes, the solubility of tungstic oxide in the bronzes, (1.) Am. Ohem. , Soc., Ch~mical Abstracts, 1926 ,-A.pril 1949. 2 and the lattice chnnges with increasing amount o'£ WO in 3 such a solid solution series. These points have not been rep orted by previous workers. Some chemical and metal­ lurgical processes are involved in this investigat ion; theories and technique of x-ray diffraction are applied 9 the samples are identified., and the structure and lat­ tice constants of lithium tungsten bronzes are found from (2) x-ray powder photogrHphs applying "straumanis' technique". (2} strauma.nis 9 M. and A. Ievins, "Die prazisionbestim­ mung von Gitterkonstanten nach der asymmetrischen Methode", Springer, Berlin, 1940; Edwards, Ann .Arbor,. )t! i~higan, 1946. REVIEW OF LITERATURE The tungsten bronze a were :first prepared by F. Woh­ ler in 1824 by reducing acid sodium tungstate with hydro­ (3) gen. Later, some other investigators also reported the preparation of tungsten bronzes of various alkali and alkaline earth metals, the methods of prepara tion may be ( 4) classified into the following three types: 1. Reduction of an acid ·tungstate with hydrogen, coal gas, tin, zinc, or iron at a high temperature --- F. Wohler and H. Wright. 2. The electrolytic reduction of a fused polytung­ state or a fused mixture of tungatic acid with a metal­ lic tungstate or of a solution of tungstic acid in a fused mixture of alkali chlorides --- c. Scheiber, A. Stayenhagen, E. Engels, L. H. a.nd H. H. X:ahlenbert and E. zettnow. 3. Melting mixtures of normal or acid tungstates with tungsten dioxide in absence of air --- o. Brunner. The exact formulas and structure of those tungsten bronzes were not known to the early workers; different formulas have been applied to the products of apparently (3) Wohler, F., pogg. Ann.~ Vol. 2, 1824, p. 350; Phil. Mag., Vol. 66, 1825, p. 263. ( 4) Mell.or, ;r. w. • "A Comprehensive Treatise on Inorgan­ ic and ~heoretioal Chemistry, Vol. 11, London, 1931, PP• 750-'761 . ;.~ 4 similar reactions. some thought that these bronzes pos- sess several sexivalent tungsten atoms ancl one quadriv- alent tungsten atom and. that their formula could gener­ ally be represented by mR o.nwo .wo • w. F. de Jong 2 3 2 first reported that the crystal structure of these bron­ zes is the same as that of perovski te ( Ca.Ti03 ), so that the formula of the bright yellow sodium tungsten bronze 5 must be Na\V'03Y _) G. Hiigg then con:finned it and showed that the tungsten in the yellow Na•W-bronze is pentava- ( 6) lent. A recent investigation of the struct ure and chem­ ical properties, the electrical conductivity o:f sodium tungsten bronzes, the maximum eolid solubility of wo3 in Na-W-bronze s, and the lattice change.s with increasing amount o:f tungstic oxide in the bronzes ·have been made ( 7) by 1v1 • E. Straumanis • . The lithium tungsten bronzes were .prepared by re­ ducing ·fuaed lithium paratungstate with tin or by elec­ trolysis o:f fused lithium paratungstate by L. A. Hallo- (6) de Jong, W. F., Zeit. Krist., Vol. 81, 1932, :P• 314. de Jong, w. F. and H. Stek, ibid, Vol. 83, 1932, p. 496. (6) Higg, G., Zeit. Physik. Chern., (B) Vol. 29, 1935, p. 192. (7) straumanis, M. E., Journ. Am. Chem. Soc., Vol. 71, 1949, PP• 679-683. straumanis, M. E. and A. Drav­ nieks, ibid', . PP• 683-687. 5 (8) (9) peau. o. Brunner and others. The products have dark olue and steel blue colors; and the crystal :forms are microscopic plates and prisms. These bronzes were assumed to have the formulas Li w o and Li wo res­ 2 4 12 2 5 15 pectively. {8) . Hallopea~. L~ A., Ann. Chim. phya., Vol. 19, 1900, :p. 117. (9) :Brumie r · o. •Bertrage zur ICe:nntnis der Wolfra.m­ aronzenff, dissertation. zurich, 1903. "· ·. ..._ ~·' . 6 THE PREPARATION OF LITHIUM: TUNGSTEl~ BRONZES 1. The starting Materials. The lithium tungsten bronzes were prepared by reduc­ ing a mixture of lithiun1 tungstate and tungstic oxide with metallic tungsten at high temperature in vacuum. The lithium tungstate was made from lithium carbon­ ate and tungstic acid by fusing at about 750°0 in air for a half hour in a platinum crucible. Li co "' wo .H o --L1 Wo • oo f + H ol •• (1) 2 3 3 2 2 4 2 2 The tungstic oxide was prepared by heating tungstic acid in air to 900°C and keeping it at ·that temperature f'or two hours.