Thermal conductivity of Gd2Zr2O7 thin films at various temperatures by using the 3ω method

Recently, Gd2Zr2O7 has been investigated as a buffer layer of YBa2Cu3O7 − x superconductor. Thermal properties of Gd2Zr2O7 below room temperature are not well known yet despite of its active studies. For the study of the thermal property at low temperature, the Gd2Zr2O7 films with various thicknesses are deposited on the Al2O3 substrate by using the RF magnetron sputtering. Thermal conductivities of Gd2Zr2O7 thin films are measured by using the 3 omega method from 80 K to room temperature. We confirm the interfacial thermal resistance and its temperature dependence. The interfacial thermal resistance decreases with increasing temperature unlike the reported temperature dependence of the thermal conductivity. The importance of interfacial effect on the thermal conductivity is being emphasized at very low temperatures.