Investigating the Role of Vacancies on the Thermoelectric Properties of EuCuSb‐Eu 2 ZnSb 2 Alloys
Investigating the Role of Vacancies on the Thermoelectric Properties of EuCuSb‐Eu 2 ZnSb 2 Alloys
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研究空位对 EuCuSb−Eu 2 ZnSb 2 合金热电性能的影响
DOI：
10.1002/anie.202301176
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Zevalkink, Alexandra
中科院分区：
文献类型：
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作者：
Chanakian, Sevan;Peng, Wanyue;Meschke, Vanessa;Ashiquzzaman Shawon, A. K. M.;Adamczyk, Jesse;Petkov, Valeri;Toberer, Eric;Zevalkink, Alexandra
具有ZrBeSi结构的AMX化合物在平面MX-层中的M-位上容许高达50%的空位浓度。在这里，我们研究了空位对整个EuCu 1 −xZn0.5xSb固溶体的热和电子性质的影响。从完全占据的蜂窝层（EuCuSb）到四分之一原子缺失的蜂窝层（EuZn0.5Sb）的转变导致蜂窝层中的非线性键膨胀，增加M和Sb-位点上的原子位移参数，以及显著的晶格软化。这与点缺陷散射的快速增加相结合，导致晶格热导率在300 K时从3 W mK− 1降低到0.5 W mK− 1。 空位对电子性质的影响更加微妙;我们看到有效质量的小幅增加，带隙的大幅增加和载流子浓度的降低。最终，当我们从EuCuSb到EuZn 0.5Sb时，最大值zT从0.09增加到0.7。
AMXcompounds with the ZrBeSi structure tolerate a vacancy concentration of up to 50 % on theM‐site in the planarMX‐layers. Here, we investigate the impact of vacancies on the thermal and electronic properties across the full EuCu1−xZn0.5xSb solid solution. The transition from a fully‐occupied honeycomb layer (EuCuSb) to one with a quarter of the atoms missing (EuZn0.5Sb) leads to non‐linear bond expansion in the honeycomb layer, increasing atomic displacement parameters on theMand Sb‐sites, and significant lattice softening. This, combined with a rapid increase in point defect scattering, causes the lattice thermal conductivity to decrease from 3 to 0.5 W mK−1at 300 K. The effect of vacancies on the electronic properties is more nuanced; we see a small increase in effective mass, large increase in band gap, and decrease in carrier concentration. Ultimately, the maximumzTincreases from 0.09 to 0.7 as we go from EuCuSb to EuZn0.5Sb.