Perovskite-type manganite-based ceramics are a promising thermoelectric material at high temperature, while their poor electrical resistivity and thermal conductivity restrict their application in thermoelectricity generators. Entropy engineering can optimize the thermoelectric performance in both electron transport and phonon scattering. RE_0.2Ca_0.2Sr_0.2Ba_0.2Y_0.2MnO₃ (RE = La, Nd, Ho, Lu) ceramics were prepared by using a solid state method. It is clearly confirmed that a high-entropy perovskite-type solid solution with some metallic oxides was obtained and all the A-site elements were dispersed homogeneously. A-site deficiency induced lattice disorders, stacking faults and sparse dislocation, were formed enhancing phonon scattering. A minimum total thermal conductivity of 0.94 W m⁻¹ K⁻¹ was obtained at 800 °C. With the increase of measured temperatures, the power factors and ZT values increased first and then decreased. The maximum power factor value of 25.3 μW m⁻¹ K⁻² was achieved at 600 °C for the La_0.2Ca_0.2Sr_0.2Ba_0.2Y_0.2MnO₃ sample. This work suggests that the strategy of high-entropy engineering paves a novel way for synergistically optimizing the thermoelectric performance of oxide ceramics.

中文翻译：

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A位缺陷改善了高熵钙钛矿锰酸盐基陶瓷的热电性能

钙钛矿型锰酸盐基陶瓷是一种很有前途的高温热电材料，但其较差的电阻率和导热性限制了其在热电发电机中的应用。熵工程可以优化电子传输和声子散射中的热电性能。RE _0.2 Ca _0.2 Sr _0.2 Ba _0.2 Y _0.2 MnO ₃(RE = La, Nd, Ho, Lu) 陶瓷采用固态法制备。可以清楚地证实，获得了具有一些金属氧化物的高熵钙钛矿型固溶体，并且所有 A 位元素均均匀分散。A位缺陷导致晶格紊乱、堆垛层错和稀疏位错，形成增强声子散射。在 800 °C 时获得了 0.94 W m ^-1 K ^-1的最小总热导率。随着实测温度的升高，功率因数和ZT值先升高后降低。_{对于 La 0.2} Ca _0.2 Sr ，在 600 °C 时实现了25.3 μW m ^-1 K ^-2的最大功率因数值_0.2 Ba _0.2 Y _0.2 MnO ₃样品。这项工作表明，高熵工程的策略为协同优化氧化物陶瓷的热电性能开辟了一条新途径。