Conductivity of Sm2TiO5 and Sm2Ti2O7

The oxygen-ion conductivity of porous materials, the coarse-grained pyrochlore-like Sm2Ti2O7 and fine-grained Sm2TiO5 compounds, produced by mechanical activation of initial oxides is studied at 400–1000 °C. The Sm2TiO5 samples contain ∼15 wt % of the nanosized pyrochlore-like Sm2TiO5 phase in addition to the rhombic phase. As determined by impedance spectroscopy, the ionic conductivities of Sm2TiO5 and Sm2Ti2O7 at 1000°C are 1.3 × 10−3 and 1.8 × 10−4 S cm−1, and the activation energies of the bulk and grainboundary conductivities of the materials are 1.04 and 1.24 eV for Sm2TiO5 and 1.69 and 1.80 eV for Sm2Ti2O7.