Phase-Transition Induced Elastic Softening and Band Gap Transition in Semiconducting PbS at High Pressure

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• 作者：Shanmin Wang ; Jianzhong Zhang ; Yi Zhang ; Andrew Alvarado ; Jeevake Attapattu ; Duanwei He ; Liping Wang ; Changfeng Chen ; Yusheng Zhao
• 刊名：Inorganic Chemistry
• 出版年：2013
• 出版时间：August 5, 2013
• 年：2013
• 卷：52
• 期：15
• 页码：8638-8643
• 全文大小：427K
• 年卷期：v.52,no.15(August 5, 2013)
• ISSN：1520-510X

文摘

We have investigated the crystal structure and phase stability, elastic incompressibility, and electronic properties of PbS based on high-pressure neutron diffraction, in-situ electrical resistance measurements, and first-principles calculations. The refinements show that the orthorhombic phase is structurally isotypic with indium iodide (InI) adopting a Cmcm structure (B33). The cubic-to-orthorhombic transition occurs at 2.1(1) GPa with a 3.8% volume collapse and a positive Clausius鈥揅lapeyron slope. Phase-transition induced elastic softening is also observed, which is presumably attributed to the enhanced metallic bonding in the B33 phase. On the basis of band structure simulations, the cubic and orthorhombic phases are typical of direct and indirect semiconductors with band gaps of 0.47(1) and 1.04(1) eV, respectively, which supports electrical resistivity measurements of an abrupt jump at the structural transition. On the basis of the resolved structure for B33, the phase transition paths for B1鈫?i>B33鈫?i>B2 involve translation of a trigonal prism in B1 and motion of the next-nearest neighbor Pb atom into {SPb₇} coordination and subsequent lattice distortion in the B33 phase.