SYNTHESIS OF V2O3 POWDER BY EVAPORATIVE DECOMPOSITION OF SOLUTIONS AND H2 REDUCTION

The evaporative decomposition of solutions method was used to form V2O5. Spraying above the congruent melting temperature of V2O5 (690-degrees-C) resulted in dense spherical particles with a smooth surface. Spraying below the V2O5 melting temperature yielded porous V2O5 powder with a rough surface. Reduction of the V2O5 to V2O3 was done in a H2 atmosphere. Spherical V2O3 powder was attained when the reduction temperature was low enough to reduce the V2O5 surface before partial sintering (necking) between V2O5 particles occurred. The resulting V2O3 particle size was smaller than the precursor V2O5 powder as expected by the differences in densities between V2O5 (rho = 3.36 g/cm-3) and V2O3 (rho = 4.87 g/cm-3).