Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.
Phys Chem Chem Phys. 2013 Oct 28;15(40):17595-600. doi: 10.1039/c3cp52942h.
Indium oxides such as In2O3 based thermoelectric ceramics exhibit a figure of merit ZT ~0.5 above 1000 K, while optimized ZnO based thermoelectrics may reach ZT ~0.3 at 1273 K. A way to further optimize the thermoelectric performance is to tune the thermal conductivity. In this work, a reduction of the thermal conductivity greater than 30% has been observed. Combining thermal conductivity measurements, Scanning Electron Microscopy (SEM) images, X-ray Absorption Fine-structure spectroscopy (XAFS) data and Full Multiple Scattering calculations, we associated the phenomenon with an effective scattering of mid- and long-wavelength phonons by embedded ZnO nano-inclusions in the In2O3 matrix. The results suggest a protocol for the synthesis of new heat-designed materials for many novel applications, such as high ZT thermoelectrics, thermal crystals, heat optics devices, etc.
氧化铟等铟基热电陶瓷在 1000K 以上表现出约 0.5 的优值系数 ZT，而优化后的氧化锌基热电材料在 1273K 时可达到约 0.3 的 ZT。进一步优化热电性能的一种方法是调整热导率。在这项工作中，观察到热导率降低了 30%以上。通过热导率测量、扫描电子显微镜 (SEM) 图像、X 射线吸收精细结构光谱 (XAFS) 数据和全多重散射计算，我们将这一现象与嵌入 In2O3 基体中的 ZnO 纳米颗粒对中长波长声子的有效散射相关联。研究结果为许多新型应用（如高热设计的高 ZT 热电材料、热晶体、热光学器件等）提供了一种新型材料的合成方案。
