Determining the influence of nanoscale decompositions in thermoelectric materials by 3D-XRDCT by fully analysing the PXRD

Hetero structured materials like Pb18AgSbTe20 exceeds a thermoelectric figure of merit of 2 due to scattering phonons at grain boundaries and associated effects. We decomposed homogeneous quenched PbAgSbTe3 to different amounts of PbTe and AgSbTe3 to understand the effects and influence of the nanoscaled spiondal decompositions on the thermoelectric material. In-situ 3D-XRDCT will show the various impacts on Seebeck coefficient, thermal and electrical conductivity of microstructures of different decomposed PbAgSbTe3. The scans will be done while the material is under working condition in a temperature gradient or under applied current to understand the effects of the segregation on properties. In addition, space resolved PXRD will give information about state of decomposition and the reflection shapes about the grain sizes.

Pb18AgSbTe20等异质结构材料因晶界处的声子散射及相关效应，其热电优值（thermoelectric figure of merit）超过2。我们将均匀淬火的PbAgSbTe3分解为不同比例的PbTe与AgSbTe3，以探究纳米级spiondal分解（spiondal decomposition）对热电材料的影响。原位3D-XRDCT将揭示不同分解程度的PbAgSbTe3微观结构对塞贝克系数（Seebeck coefficient）、热导率及电导率的多种作用。扫描将在材料处于温度梯度或外加电流的工作条件下进行，以理解偏析对材料性能的影响。此外，空间分辨PXRD将提供关于分解状态及晶粒尺寸相关反射峰形状的信息。