Department of Materials Science and Engineering and Institute of Materials Genome & Big Data , Harbin Institute of Technology , Shenzhen 518055 , P.R. China.
Key Laboratory of Interface Science and Engineering in Advanced Materials , Taiyuan University of Technology, Ministry of Education , Taiyuan 030024 , China.
ACS Appl Mater Interfaces. 2019 Oct 16;11(41):37741-37747. doi: 10.1021/acsami.9b12748. Epub 2019 Oct 7.
Zintl phase compounds CaZnSb have promising thermoelectric properties due to their complex crystal structure and tunable interstitial Zn. In this work, we prepared nominal CaZnSb ( = 0.5, 0.6, 0.7, and 0.8) using ball milling and hot pressing. Further decreased lattice thermal conductivity was obtained by isoelectronic substitution of Eu on the selective Ca site, which is farther away from the framework of [ZnSb] for the smaller disturbance of carrier transport. Together with the intensively enhanced carrier mobility, which is attributed to the decreased effective mass and the increased interstitial Zn by inclusion of Eu, an increased peak value to ∼1.05 at 773 K and an enhanced average value to ∼0.73 from 300 to 823 K were achieved in CaEuZnSb.
由于其复杂的晶体结构和可调的间隙 Zn，Zintl 相化合物 CaZnSb 具有有前景的热电性能。在这项工作中，我们使用球磨和热压法制备了名义 CaZnSb（=0.5、0.6、0.7 和 0.8）。通过在选择性 Ca 位上进行 Eu 的等电子取代，进一步降低了晶格热导率，这是因为 Eu 离 [ZnSb] 框架更远，对载流子输运的干扰更小。与载体迁移率的显著增强相结合，这归因于有效质量的降低和 Eu 的掺入增加了间隙 Zn，在 CaEuZnSb 中实现了在 773 K 时高达 ∼1.05 的峰值 值和在 300 到 823 K 时平均 值提高到 ∼0.73。
