The Thermophysical Properties of (Gd1-xLax)2Zr2O7 Synthesized by the Molten Salt Method

Gd2Zr2O7Gd2Zr2O7, as a type of materialMaterials applied for thermal barrier coatingsThermal barrier coatings, has received widespread attention. However, due to its low thermal expansion coefficient, dopingDoping with rare earthRare earth oxides is usually used to improve the property. In this study, La-doped (Gd1-xLax)2Zr2O7 was prepared using the molten salt methodMolten salt method. The results indicate that for x < 0.5, (Gd1-xLax)2Zr2O7 exhibits a fluorite structureStructure, while for x ≥ 0.5, it exhibits a pyrochlore phase. Dense ceramic bulk samples with high density (93%) were obtained by pressing the powder (Gd1-xLax)2Zr2O7 and sinteringSintering, for measurement of thermal conductivity and thermal expansion coefficient. The result revealed that (Gd1-xLax)2Zr2O7 (x ≤ 0.5) significantly reduces the thermal conductivity of Gd2Zr2O7Gd2Zr2O7 and increases its thermal expansion coefficient. Simultaneously, with the increase in x, the thermal expansion coefficient exhibited a trend of initially increasing and then decreasing. When x was 0.5, the maximum thermal expansion coefficient reached 11 × 10−6 K−1, increased by 10% compared to Gd2Zr2O7Gd2Zr2O7.