Thermal conductivity of rare-earth scandates in comparison to other oxidic substrate crystals

Abstract

High-temperature thermal properties of three neighboring rare-earth scandates DyScO3, TbScO3 and GdScO3 were compared to La0.29Sr0.71Al0.65Ta0.35O3 (LSAT) and sapphire. To calculate thermal conductivity, heat capacity and thermal diffusivity were measured by differential scanning calorimetry and laser flash technique, respectively. DyScO3 and TbScO3 showed an untypical rise in the thermal conductivity above 900 K, while for GdScO3, LSAT and sapphire the expected decrease at elevated temperatures could be observed.