On the relevance between fine structure and enhanced performance of skutterudite thermoelectric materials: X-ray spectroscopy studies

详细信息    查看全文

• 作者：Ping WeiAuthor Vitae ; Wenyu Zhao ; ^{wyzhao@whut.edu.cn" class="auth_mail" title="E-mail the corresponding author}Author Vitae ; Dingguo Tang ; Wanting Zhu ; Xiaolei Nie ; Qingjie Zhang ; ^{zhangqj@whut.edu.cn" class="auth_mail" title="E-mail the corresponding author}Author Vitae
• 关键词：Thermoelectric materials ; X-ray absorption near-edge structure ; Extended X-ray absorption fine structure ; Band convergence
• 刊名：Journal of Materiomics
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：2
• 期：3
• 页码：280-289
• 全文大小：2459 K

文摘

The relevance between the fine structure and transport performance of thermoelectric materials can be revealed by X-ray spectroscopy including X-ray absorption and emission spectra as an effective tool. In this paper, the experimental spectra of extended X-ray absorption fine structure (EXAFS), X-ray absorption near-edge structure (XANES), and valence-band X-ray photoelectron spectroscopy (XPS) of Ba and In double-filled skutterudites (Ba_xIn_yCo₄Sb₁₂) were analyzed via the first-principles calculation and spectrum simulation. The atomic-scale fine structures indicate that the rectangle Sb₄ rings become square when the total filing fraction of Ba and In increases. The transition of Sb₄ rings leads to the band convergence and density of states (DOS) increase of the SbSb ppσ bonding and ppπ^∗ antibonding states. The enhanced TE performance of Ba_xIn_yCo₄Sb₁₂ is essentially attributed to the band convergence, the increased DOS near the Fermi level, and the resonant phonon scattering of Ba and In fillers.