Structure, thermal stability and electrical conductivity of CaMoO4+δ

Abstract Single-phase tetragonal scheelite CaMoO 4 (space group, Pmmm ) was prepared via the conventional solid state reaction method. The oxidation state of the transition metal species for the as-sintered CaMoO 4 was analyzed by X-ray photoelectron spectroscopy (XPS). The average thermal expansion coefficient was measured as about 11 × 10 −6 K −1 over the temperature range of 303–1373 K. From the thermodynamic point of view, the phase diagram for CaMoO 4 was constructed by computing the equilibrium phase boundaries. Finally, the electrical conductivity of CaMoO 4 was also investigated by an AC impedance analyzer. The activation energy of bulk conductivity for CaMoO 4 was 2.1 eV.