HfO2–Sm3TaO7 ceramics are prepared through a solid-state reaction method. The X-ray diffraction and structural refinement show that the phase structures of HfO2–Sm3TaO7 ceramics are an ordered orthorhombic phase and the space groups are belonging to Ccmm. The degree of the structural disorder increases with increasing HfO2 content. The solid solution mechanism reveals that Hf4+ exists in the form of interstitial ions that cause crystal expansion when the doping content is less than 4 mol%. When the doping concentration of HfO2 ≥ 4 mol%, the Hf4+ ions can substitute an equal number of Sm3+ and Ta5+ ions. The phase transition of Sm3TaO7 ceramics is removed with increasing HfO2 content, and the 8 mol% HfO2–Sm3TaO7 ceramics have a high thermal expansion coefficient of 10.2 × 10−6 K−1 at 1200 °C. The 2 mol% HfO2–Sm3TaO7 ceramics have the lowest thermal conductivity (1.03 W/m K at 900 °C), which is lower than previous research of the 7–8 YSZ. The outstanding thermophysical properties of HfO2–Sm3TaO7 ceramics indicate that they are potential thermal-barrier coating materials.

HfO 2 -Sm 3 TaO 7陶瓷是通过固态反应方法制备的。X射线衍射和结构细化表明，HfO 2 -Sm 3 TaO 7陶瓷的相结构为有序正交晶相，空间群为Ccmm。HfO 2含量越高，结构紊乱的程度越大。固溶机理表明，Hf 4+以间隙离子的形式存在，当掺杂量小于4 mol％时会引起晶体膨胀。当HfO 2的掺杂浓度≥4 mol％时，Hf 4+离子可以替代相等数量的Sm 3+和Ta 5+离子。随着HfO 2含量的增加，Sm 3 TaO 7陶瓷的相变被去除，并且8 mol％HfO 2 -Sm 3 TaO 7陶瓷在1200°C时具有10.2×10 -6 K -1的高热膨胀系数。2 mol％HfO 2 –Sm 3 TaO 7陶瓷的导热系数最低（900°C时为1.03 W / m K），低于以前的7-8 YSZ研究。HfO 2 -Sm 3 TaO的杰出热物理性质7种陶瓷表明它们是潜在的热障涂层材料。