High entropy engineering has been widely used to optimize properties of various materials, and we improve comprehensive performance of rare-earth tantalates RETaO₄ (RE is rare earth) by changing configurational entropy in this work. Four medium/high entropy RETaO₄ (M/HERT) are successfully prepared, and the variations of disorders and distortion degree of lattices with the increasing configurational entropy are described in detail. It is revealed that M/HERT with the highest configurational entropy does not correspond to the best comprehensive properties. Unexpected variations in properties of M/HERT compared to RETaO₄ are observed. By comparing with values obtained from rule of mixture (ROM), it is believed that the cocktail effect exists in M/HERT. The synergistic optimizations of thermo-mechanical properties are realized, including reducing thermal conductivity, increasing thermal expansion coefficients (TECs), and enhancing mechanical properties. M/HERT exhibit excellent high temperature stability and provide a good thermal insulation gradient, which is significant for high-temperature applications of RETaO₄. This work serves as an important part for thermal barrier coatings materials with high working temperatures and low thermal conductivity.

中文翻译：

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高熵工程提高了稀土钽酸盐的热机械性能：鸡尾酒效应的影响


高熵工程已被广泛用于优化各种材料的性能，在这项工作中，我们通过改变构型熵来提高稀土钽 RETaO₄（RE 是稀土）的综合性能。成功制备了 4 种中/高熵 RETaO₄ （M/HERT），并详细描述了随着构型熵的增加，晶格的无序变化和畸变程度。结果表明，具有最高构型熵的 M/HERT 并不对应于最佳综合性质。观察到 M/HERT 与 RETaO₄ 相比，其性能发生了意想不到的变化。通过与从混料规则 （ROM） 获得的值进行比较，可以相信 M/HERT 中存在鸡尾酒效应。实现了热机械性能的协同优化，包括降低导热系数、增加热膨胀系数 （TEC） 和增强机械性能。M/HERT 表现出优异的高温稳定性，并提供良好的隔热梯度，这对于 RETaO₄ 的高温应用具有重要意义。这项工作是高工作温度和低导热性热障涂层材料的重要组成部分。