当前位置：
X-MOL 学术
›
ACS Appl. Mater. Interfaces
›
论文详情
Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Ag-Segregation to Dislocations in PbTe-Based Thermoelectric Materials
ACS Applied Materials & Interfaces ( IF 8.3 ) Pub Date : 2018-01-16 00:00:00 , DOI: 10.1021/acsami.7b17142 Yuan Yu 1, 2 , Siyuan Zhang 3 , Antonio Massimiliano Mio 1 , Baptiste Gault 3 , Ariel Sheskin 4 , Christina Scheu 3 , Dierk Raabe 3 , Fangqiu Zu 2 , Matthias Wuttig 1, 5 , Yaron Amouyal 4 , Oana Cojocaru-Mirédin 1, 3
ACS Applied Materials & Interfaces ( IF 8.3 ) Pub Date : 2018-01-16 00:00:00 , DOI: 10.1021/acsami.7b17142 Yuan Yu 1, 2 , Siyuan Zhang 3 , Antonio Massimiliano Mio 1 , Baptiste Gault 3 , Ariel Sheskin 4 , Christina Scheu 3 , Dierk Raabe 3 , Fangqiu Zu 2 , Matthias Wuttig 1, 5 , Yaron Amouyal 4 , Oana Cojocaru-Mirédin 1, 3
Affiliation
|
Dislocations have been considered to be an efficient source for scattering midfrequency phonons, contributing to the enhancement of thermoelectric performance. The structure of dislocations can be resolved by electron microscopy whereas their chemical composition and decoration state are scarcely known. Here, we correlate transmission Kikuchi diffraction and (scanning) transmission electron microscopy in conjunction with atom probe tomography to investigate the local structure and chemical composition of dislocations in a thermoelectric Ag-doped PbTe compound. Our investigations indicate that Ag atoms segregate to dislocations with a 10-fold excess of Ag compared with its average concentration in the matrix. Yet the Ag concentration along the dislocation line is not constant but fluctuates from ∼0.8 to ∼10 atom % with a period of about 5 nm. Thermal conductivity is evaluated applying laser flash analysis, and is correlated with theoretical calculations based on the Debye–Callaway model, demonstrating that these Ag-decorated dislocations yield stronger phonon scatterings. These findings reduce the knowledge gap regarding the composition of dislocations needed for theoretical calculations of phonon scattering and pave the way for extending the concept of defect engineering to thermoelectric materials.
中文翻译：
Ag偏析到PbTe基热电材料中的位错
位错已被认为是散射中频声子的有效来源，有助于提高热电性能。位错的结构可以通过电子显微镜解决，而其化学组成和装饰状态却鲜为人知。在这里，我们将透射菊池衍射和（扫描）透射电子显微镜与原子探针层析成像技术进行关联，以研究热电掺杂Ag的PbTe化合物中位错的局部结构和化学组成。我们的研究表明，与原子在基体中的平均浓度相比，银原子以10倍过量的银偏析成位错。然而，沿着位错线的Ag浓度不是恒定的，而是以约5nm的周期在约0.8至约10原子％之间波动。使用激光闪光分析评估热导率，并将其与基于Debye–Callaway模型的理论计算相关联，表明这些用Ag装饰的位错会产生更强的声子散射。这些发现减少了关于声子散射的理论计算所需的位错组成的知识鸿沟，并为将缺陷工程学的概念扩展到热电材料铺平了道路。
更新日期：2018-01-16
中文翻译：
Ag偏析到PbTe基热电材料中的位错
位错已被认为是散射中频声子的有效来源，有助于提高热电性能。位错的结构可以通过电子显微镜解决，而其化学组成和装饰状态却鲜为人知。在这里，我们将透射菊池衍射和（扫描）透射电子显微镜与原子探针层析成像技术进行关联，以研究热电掺杂Ag的PbTe化合物中位错的局部结构和化学组成。我们的研究表明，与原子在基体中的平均浓度相比，银原子以10倍过量的银偏析成位错。然而，沿着位错线的Ag浓度不是恒定的，而是以约5nm的周期在约0.8至约10原子％之间波动。使用激光闪光分析评估热导率，并将其与基于Debye–Callaway模型的理论计算相关联，表明这些用Ag装饰的位错会产生更强的声子散射。这些发现减少了关于声子散射的理论计算所需的位错组成的知识鸿沟，并为将缺陷工程学的概念扩展到热电材料铺平了道路。
京公网安备 11010802027423号