Thermal insulation performance of Ce‐Y co‐doped ZrO ₂ solid solutions under HPHT conditions

Abstract This study investigates the thermal insulation performance of CeO 2 and Y 2 O 3 co‐doped ZrO 2 solid solutions cerium‐yttria co‐doped stabilized zirconia (CYZ), prepared via the solid‐state reaction method. A comparative assessment was conducted between CYZ and Y 2 O 3 ‐ZrO 2 solid solutions yttria‐stabilized zirconia (YSZ) under 10 GPa pressure conditions. The results reveal that the temperature change efficiency of CYZ is significantly enhanced, compared to YSZ. Under equivalent heating power conditions, the maximum temperature differential within the cavity for CYZ (with 25 wt.% CeO 2 doping) reached 300°C, marking a 20% improvement over YSZ. This implies that employing CYZ as an insulation material could reduce heating energy consumption by approximately 20%. The notable lattice distortion induced by CeO 2 incorporation enhances phonon scattering under high‐pressure high‐temperature conditions, effectively reducing heat transfer. Furthermore, the Debye temperature of CYZ was determined to be approximately 800°C under 10 GPa compression. Above this temperature, CYZ exhibits a characteristic 1/T dependence, with its thermal insulation performance improving as temperature increases, whereas YSZ demonstrates minimal variation in its insulation characteristics. And leveraging the excellent high‐temperature thermal insulation properties of CYZ, it is expected to achieve cavity temperatures exceeding 2500°C under 10 GPa pressure.