Temperature dependence of the thermal conductivity of Gd2Zr2O7 thin films

Gd2Zr2O7 has been known to be a promising candidate for a future thermal-barrier-coating material and for use as a buffer layer for YBa2Cu3O7−x. This study focuses on Gd2Zr2O7 films deposited on an Al2O3 substrates by using radio-frequency magnetron sputtering, especially its thermal conductivity at various temperatures from 80 K to 300 K. Prior to the measurement with the Gd2Zr2O7 films, thermal conductivity measurements at low temperatures were performed with n-type Si and Al2O3 whose thermal properties are well known. The thermal conductivity of the Gd2Zr2O7 film increases as the temperature increases from 80 K to 300 K, and this temperature region is below its Debye temperature. The film exhibits a thermal conductivity lower than the value reported at room temperature.