Metastable hexagonal vanadium molybdate study

The solid solution of vanadium in hexagonal molybdenum oxide has never prev iously been completely studied; no information has been given about the sol ubility limit or the thermal stability of the system. In this work, we have determined that the solubility limit is reached with the following composi tion: (NH4)(0.13)V0.13Mo0.87O3. Our samples have been obtained by a soft ch emistry method. The obtained precipitates have been processed and analyzed with several techniques, We have shown that the introduction of vanadium in the h-MoO3 structure has several effects, on the thermal stability of the metastable mixed oxide, on the morphology, as well as on the lattice parame ters. (C) 2000 Academic Press.