Electronic, magnetic and structural properties of A2VMoO6 perovskites (A = Ca, Sr)

The perovskites Sr2VMoO6 and Ca2VMoO6 have been synthesized by liquid-mix technique in citrate melts, and their electronic, magnetic and structural properties have been investigated. No signs of V/Mo ordering are seen by synchrotron X-ray powder diffraction, but despite the chemical disorder both oxides are highly conductive and Pauli paramagnetic. Electrical conductivities of these solid solutions are comparable or higher than those reported for polycrystalline AMoO(3) end members. It is suggested that the delocalized metallic conductivity of these compounds with two different transition-metal atoms implies valence equilibrium between the degenerate oxidation-state couples V4+Mo4+ and V3+Mo5+. (C) 2006 Elsevier Inc. All rights reserved.