Tin–molybdenum oxides. A study by X-ray diffraction, Mössbauer spectroscopy, and electron spin resonance

Abstract

The formation of tin–molybdenum oxides by the calcination of precipitates involves the initial dehydration of amorphous gels to give, at low temperatures, highly-disordered rutile-type solids capable of accommodating high concentrations of molybdenum. Excess molybdenum segregates, under the influence of moderate thermal treatment, from the crystallising rutile-type phase to form macroscopically distinguishable molybdenum(VI) oxide which volatilises at higher temperatures. Prolonged calcination at high temperature gives materials which may be described as solid solutions containing low concentrations of molybdenum(V) in the tin(IV) oxide rutile-type lattice.