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

Malliakas, Christos D.; Poineau, Frederic; Johnstone, Erik V.; Weck, Philippe F.; Kim, Eunja; Scott, Brian L.; Forster, Paul M.; Kanatzidis, Mercouri G.; Czerwinski, Kenneth R.; Sattelberger, Alfred P.

doi:10.1021/ja408459k

DOE OSTI · 1338191

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

Malliakas, Christos D.·Poineau, Frederic·Johnstone, Erik V.·Weck, Philippe F.·Kim, Eunja·Scott, Brian L.·Forster, Paul M.·Kanatzidis, Mercouri G.·Czerwinski, Kenneth R.·Sattelberger, Alfred P.

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Abstract

A second polymorph of technetium dichloride, β-TcCl 2 , has been synthesized from the reaction of Tc metal and chlorine in a sealed tube at 450 °C. The crystallographic structure and physical properties of β-TcCl 2 have been investigated. The structure of β-TcCl 2 consists of infinite chains of face sharing [Tc 2 Cl 8 ] units; within a chain, the T c ≡T c vectors of two adjacent [T c 2 Cl 8 ] units are ordered in the long-range where perpendicular and/or parallel arrangement of Tc≡Tc vectors yields a modulated structure. Resistivity and Seebeck measurements performed on a β-T c Cl 2 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 T c Cl 2 .

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Malliakas, Christos D., Poineau, Frederic, Johnstone, Erik V., Weck, Philippe F., Kim, Eunja, Scott, Brian L., Forster, Paul M., Kanatzidis, Mercouri G., Czerwinski, Kenneth R., Sattelberger, Alfred P.. 2013-09-20. β-Technetium Dichloride: Solid-State Modulated Structure, Electronic Structure, and Physical Properties. https://doi.org/10.1021/ja408459k

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