Alkali Metal Tungsten Bronzes
Alkali Metal Tungsten Bronzes

Author: Kalpana Rani Dey

Publisher: LAP Lambert Academic Publishing

Published: 2011-12-01

Total Pages: 144

ISBN-13: 9783846595268

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Among the transition metal oxides, tungsten bronzes have attained considerable attention due to their chemical, electrical and optical properties which depend on the type of alkali-metal atom and its composition. The term tungsten bronze is applied to the non-stoichiometric compounds of general formula MxWO3 (0 > x > 1), where M is an alkali-metal atom. The common structural feature of these materials is the WO6 octahedra which are repeated along three directions through corner sharing. This structural arrangement provides various kinds of tunnels, which are at least partly occupied by alkali metal atoms. These materials undergo one or more structural phase transitions depending on the content of alkali metal x. The main part of this book is focused on LixWO3-PTB, in order to explore the stability field in the conventional solid state synthesis techniques and to investigate in particular their spectral properties. For polarised micro reflectivity, single crystals of LixWO3 are also prepared by chemical vapour transport method. The spectral and structural properties of Nb-doped and Mo-doped alkali metal tungsten bronzes, AxMyW1-yO3 (A = Li, Na, Cs and M = Nb, Mo) are also discussed.

Analytical Chemistry of Molybdenum and Tungsten
Analytical Chemistry of Molybdenum and Tungsten

Author: W. T. Elwell

Publisher: Elsevier

Published: 2013-10-22

Total Pages: 290

ISBN-13: 1483280616

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International Series of Monographs in Analytical Chemistry, Volume 47: Analytical Chemistry of Molybdenum and Tungsten describes the chemical and instrumental methods of analysis of molybdenum and tungsten. This book is composed of 15 chapters that particularly consider detailed methods for determining these metals in typical samples and their alloys by both classical and modern techniques. The opening chapters discuss the history, occurrence, physico-chemical properties, and applications of molybdenum and tungsten. The succeeding chapters deal with the metals’ sampling, decomposition, separation, and qualitative detection. Considerable chapters are devoted to various chemical and instrumental methods for their analysis, including gravimetry, titrimetry, colorimetry, polarography, amperometry, coulometry, emission and atomic absorption spectroscopy, X-ray spectrophotometry, mass spectrometry, and radiochemical methods. The concluding chapter examines the determination of impurities and alloying elements. This book will prove useful to analytical and inorganic chemists, as well as analytical and inorganic chemistry students.