Narrow Gap Semiconducting Germanium Allotrope from the Oxidation of a Layered Zintl Phase in Ionic Liquids

Zhongjia Tang; Alexander P Litvinchuk; Melissa Gooch; Arnold M Guloy

doi:10.1021/jacs.8b03503

Narrow Gap Semiconducting Germanium Allotrope from the Oxidation of a Layered Zintl Phase in Ionic Liquids

J Am Chem Soc. 2018 Jun 6;140(22):6785-6788. doi: 10.1021/jacs.8b03503. Epub 2018 May 25.

Authors

Zhongjia Tang¹, Alexander P Litvinchuk^{2

3}, Melissa Gooch^{2

3}, Arnold M Guloy^{1

3}

Affiliations

¹ Department of Chemistry , University of Houston , Houston , Texas 77204-5003 , United States.
² Department of Physics , University of Houston , Houston , Texas 77204-5005 , United States.
³ Texas Center for Superconductivity , University of Houston , Houston , Texas 77204-5002 , United States.

PMID: 29782155
DOI: 10.1021/jacs.8b03503

Abstract

A metastable germanium allotrope, Ge(oP32), was synthesized as polycrystalline powders and single crystals from the mild-oxidation/delithiation of Li₇Ge₁₂ in ionic liquids. Its crystal structure, from single crystal X-ray diffraction ( Pbcm, a = 8.1527(4) Å, b = 11.7572(5) Å, c = 7.7617(4) Å), features a complex covalent network of 4-bonded Ge, resulting from a well-ordered topotactic oxidative condensation of [Ge₁₂]^7- layers. It is a diamagnetic semiconductor ( E_g = 0.33 eV), and transforms exothermically and irreversibly to α-Ge at 363 °C. This demonstrates the potential of ionic liquids as reactive media in the mild oxidation of Zintl phases to new highly crystallized modifications of elements and simple compounds.

Publication types

Research Support, Non-U.S. Gov't