PNNL

Abstract

The effect of 120 keV He++D+-ion irradiation on the thermal conductivity of ceramic ?-LiAlO2 is studied with time-domain thermoreflectance (TDTR) at temperatures between 300 and 700 K. The thermal conductivity of single crystal ?-LiAlO2 is 13.5 W/(m•K) at 300 K, and scales with temperature like 1/T. The thermal conductivity of unirradiated polycrystalline ?-LiAlO2 is 7.4 W/(m•K) Irradiation at fluences of 1×, 5×, and 10×1016 ions/cm2 decreases the thermal conductivity by ˜31%, 76%, and 88%. The effect of irradiation is saturated at ion fluences of 1017 ions/cm2. Irradiation decreases the temperature dependence of the thermal conductivity. For ion fluences larger than 1017 ions/cm2, the thermal conductivity reaches a minimum value of ˜ 1 W/(m•K) that is independent of temperature.