The effect of nano-twins on the thermoelectric properties of Ga2O3(ZnO)m (m = 9, 11, 13 and 15) homologous compounds
The effect of nano-twins on the thermoelectric properties of Ga2O3(ZnO)m (m = 9, 11, 13 and 15) homologous compounds
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DOI：
10.1016/j.jeurceramsoc.2020.07.021
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发表时间：
2020-12
影响因子：
5.7
通讯作者：
D. Alvarez-Ruiz;F. Azough;T. Slater;S. Day;R. Freer
中科院分区：
文献类型：
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作者：
D. Alvarez-Ruiz;F. Azough;T. Slater;S. Day;R. Freer
Ga 2 O3（ZnO）m（m=整数）同系化合物是天然存在的纳米结构材料。它们固有的低导热性使它们对热电应用具有吸引力。采用固相反应法制备了高密度Ga 2 O3（ZnO）m（m= 9，11，13和15）单相陶瓷。对于所有组合物，观察到平行于X轴的纳米尺寸的孪晶状V形边界（顶角为60°）。原子分辨率Z衬度成像和EDS分析表= 15显示Ga离子在V形孪晶界界面处的偏聚。热和电荷输运性质取决于m的值。m = 9的组合物在300 K-900 K下表现出非常低的晶格热导率，为2至1.5 W/m.K; m =15的组合物表现出140 μW/m的功率因子改善。K2在900 K导致热电优值（ZT值）为0.055。本研究探讨了改善这些材料热电性能的结构变体和途径
Ga2O3(ZnO)m(m= integer) homologous compounds are naturally occurring nanostructured materials. Their intrinsically low thermal conductivity makes them attractive for thermoelectric applications. High density Ga2O3(ZnO)m(m= 9, 11, 13, and 15) single phase ceramics were prepared by solid-state reaction. Nano-sized, twin-like V-shaped boundaries parallel tob-axis (apex angle ∼ 60°) were observed for all compositions. Atomic resolutionZ-contrast imaging and EDS analysis form= 15 showed segregation of Ga ions at the interface of V-shaped twin boundaries. Thermal and charge transport properties depend on the value ofm. Compositions withm= 9 exhibited very low lattice thermal conductivity of 2 to 1.5 W/m.K at 300 K–900 K; compositions withm=15 showed improved power factor of 140 μW/m. K2at 900 K leading to a thermoelectric figure of merit (ZTvalue) of 0.055. This study explores the structural variants and routes to improve the thermoelectric properties of these materials