Synthesis, thermal conductivities and phase stability of Gd3TaO7 and La doped Gd3TaO7 ceramics

Gd3TaO7 and La doped Gd3TaO7 (LaGd2TaO7) were synthesized through solid-state reaction at 1550 °C for 10 h, and subsequently the thermal conductivity and phase stability of both ceramics were investigated. The results indicate that both Gd3TaO7 and LaGd2TaO7 ceramics exhibited single pyrochlore-type crystal structure. The thermal conductivity for LaGd2TaO7 was 1.05 W m−1 K−1 at 800 °C, about 15% lower than that for Gd3TaO7. Gd3TaO7 and La doped Gd3TaO7 remained good phase stability when heating from room temperature to 1400 °C.