Thermal expansion and conductivity of RE2Sn2O7 (RE = La, Nd, Sm, Gd, Er and Yb) pyrochlores

The calculated cohesive energies and formation enthalpies of Rare earth stannate (RE2Sn2O7) compounds are in good agreement with the corresponding experimental values. The thermal expansion coefficients (TECs) of rare earth stannates are 7-9 x 10(-6) K-1 at high temperature. The results show that local spin density approximation predicts smaller TECs than the real values. The computed thermal conductivity of RE2Sn2O7 is 1.8-2.5 W (m . K)(-1) at 1273 K using the Slack-Clarke model, indicating that RE2Sn2O7 compounds exhibit good thermal insulating properties at high temperature. Published by Elsevier Ltd. on behalf of Acta Materialia Inc.