Precipitate morphologies of pseudobinary - thermoelectric compounds

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• 作者：Yunya Liu ; Luqin Chen ; Jiangyu Li
• 关键词：Thermoelectric compound ; Sb2Te3Sb2Te3&ndash ; PbTePbTe ; Precipitate morphology ; Equivalent inclusion method ; Phase-field simulation
• 刊名：Acta Materialia
• 出版年：15 February, 2014
• 年：2014
• 卷：65
• 期：Complete
• 页码：308-315
• 全文大小：3365 K

文摘

Nanostructured thermoelectric materials offer promising levels of conversion efficiency due to enhanced phonon scattering at interfaces, and a good understanding of the formation and evolution of their microstructure is important. In this paper, we analyze precipitate morphologies of pseudobinary - thermoelectric compounds using energetics analysis, combining the equivalent inclusion method and phase-field simulations. It is found that precipitates embedded in matrix tend to be lamellar, ribbon-like or needle-like in shape to minimize the potential energy, and tend to lie on a crystallographical cone around the body diagonal of the lattice. Furthermore, phase-field simulations reveal that interfacial energy plays an important role in precipitate morphology, with low interfacial energy favoring needle-like precipitates, while intermediate interfacial energy favors ribbon-like ones. Good agreements with experimental data and compatibility analysis are observed.