LOW-TEMPERATURE CHEMICAL APPROACHES FOR SYNTHESIZING SULFIDES AND NITRIDES OF REACTIVE TRANSITION-METALS

The advent of the sol-gel technique over the past several decades and the recognition of its excellent flexibility for synthesizing a large variety of oxide ceramics and glasses in both bulk and thin-film forms has generated considerable interest in using solution-based processes to prepare ceramic materials, Because of the success of the sol-gel t echnique, a number of other chemical processes have been developed uti lizing metalorganic/organometallic starting materials to create molecu larly architectured precursors, which have proven effective in synthes izing both oxide and non-oxide materials, In the present study, two di fferent chemical approaches have been implemented to synthesize non-ox ides (sulfides and nitrides) of reactive transition-metal elements, Ac cordingly, a novel thio-sol-gel process for preparing TiS2 and NbS2 po wders has been studied, In the case of TiS2 synthesis, the chemical re action has been examined in detail using Fourier-transform infrared sp ectroscopy (FTIR) and gas chromatography (GC), The effects of modifica tion of the titanium precursor on the morphology of the final sulfide have also been investigated and are discussed, A second, more generali zed process has been developed for synthesizing homogeneous precursors in multicomponent systems, Its utilization in preparing ternary nitri des has been demonstrated, and is also presented. (C) 1997 by John Wil ey & Sons, Ltd.