尾-Technetium Dichloride: Solid-State Modulated Structure, Electronic Structure, and Physical Properties

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• 作者：Christos D. Malliakas ; Frederic Poineau ; Erik V. Johnstone ; Philippe F. Weck ; Eunja Kim ; Brian L. Scott ; Paul M. Forster ; Mercouri G. Kanatzidis ; Kenneth R. Czerwinski ; Alfred P. Sattelberger
• 刊名：Journal of the American Chemical Society
• 出版年：2013
• 出版时间：October 23, 2013
• 年：2013
• 卷：135
• 期：42
• 页码：15955-15962
• 全文大小：528K
• 年卷期：v.135,no.42(October 23, 2013)
• ISSN：1520-5126

文摘

A second polymorph of technetium dichloride, 尾-TcCl₂, has been synthesized from the reaction of Tc metal and chlorine in a sealed tube at 450 掳C. The crystallographic structure and physical properties of 尾-TcCl₂ have been investigated. The structure of 尾-TcCl₂ consists of infinite chains of face sharing [Tc₂Cl₈] units; within a chain, the Tc鈮c vectors of two adjacent [Tc₂Cl₈] units are ordered in the long-range where perpendicular and/or parallel arrangement of Tc鈮c vectors yields a modulated structure. Resistivity and Seebeck measurements performed on a 尾-TcCl₂ single crystal indicate the compound to be a p-type semiconductor while a magnetic susceptibility measurement shows technetium dichloride to be diamagnetic. A band gap of 0.12(2) eV was determined by reflectance spectroscopy measurements. Theoretical calculations at the density functional level were utilized for the investigation of other possible stable forms of TcCl₂.