Structure, thermal stability and electrical properties of Ca(V0.5Mo0.5)O3 as solid oxide fuel cell anode

The Ca(V_0.5Mo_0.5)O₃ perovskite has been prepared in order to study its potential use as anode in SOFC. The crystal structure has been refined, by neutron powder diffraction, in the orthorhombic Pbnm space group (no. 62). The electrical conductivity values were over 525 S cm⁻¹ in the studied temperature range (25-800 °C). The sample is stable under reducing working conditions (H₂/N₂ 10:90, 25-900 °C). This orthorhombic phase transforms at 500 °C in air to the tetragonal I4₁/a scheelite phase. This transition is reversible and, due to the fact that the thermal expansion coefficients of both, the reduced and oxidized phases, are very similar and match well with those of the other cell components ((10-13) × 10⁻⁶ K⁻¹) this materials are presented as excellent candidates as anodes in SOFCs.