High-temperature thermal properties of three neighboring rare-earth scandates DyScO$_3$, TbScO$_3$ and GdScO$_3$ were compared to La$_{ 0.29}$Sr$_{ 0.71}$Al$_{ 0.65}$Ta$_{ 0.35}$O$_3$ (LSAT) and sapphire. To calculate thermal conductivity, heat capacity and thermal diffusivity were measured by differential scanning calorimetry and laser flash technique, respectively. DyScO$_3$ and TbScO$_3$ showed an untypical rise in the thermal conductivity above 900\,K, while for GdScO$_3$, LSAT and sapphire the expected decrease at elevated temperatures could be observed. These results lead to the proposal of a new type of heat transport by migrating ions.
Categories: cond-mat.mtrl-sci