STUDIES ON LAYER DISORDER, MICROSTRUCTURAL PARAMETERS AND OTHER PROPERTIES OF TUNGSTEN-SUBSTITUTED MOLYBDENUM-DISULFIDE, MO1-XWXS2 0-LESS-THAN-OR-EQUAL-TO-X-LESS-THAN-OR-EQUAL-TO-1)

The present paper deals with the preparation of tungsten-substituted m olybdenum disulfide, Mo1-xWxS2 (0 less than or equal to x less than or equal to 1) compounds and their characterization by various physicoch emical methods. X-ray studies confirmed that these compounds crystalli zed in a layer type of hexagonal structure. X-ray line profile analysi s techniques such as the method of variance and Fourier analysis have been used for microstructural characterization of these compounds to f ind out information about particle size, r.m.s. strain, variability of interlayer spacing, fraction of planes affected by such defects, disl ocation density, stacking fault probability and radial distribution fu nction analysis for calculating coupling constants and mean-square dis placements, etc. Room-temperature magnetic susceptibility measurements and thermoelectric power experiments and temperature variation of con ductivity (25-350 degrees C) confirmed, respectively, diamagnetic n- a nd p-type semiconducting behaviour for Mo1-xWxS2. Thermal stability be haviour of these compounds in air and inert atmosphere has also been c arried out up to 1000 degrees C. These studies indicated that the comp ounds are nearly stable up to 1000 degrees C in inert atmosphere. wher eas, in air, oxidative degradation of these compounds started at 400 d egrees C. The nature of the oxidized products has also been studied by X-ray analysis. Scanning electron micrograph studies are also reporte d here. (C) 1997 Elsevier Science S.A.