Publication Date

4-1-2021

Department

Ames Laboratory; Chemistry

Campus Units

Ames Laboratory, Chemistry

OSTI ID+

1777937

Report Number

IS-J 10461

DOI

10.1021/acs.inorgchem.0c03636

Journal Title

Inorganic Chemistry

Volume Number

60

Issue Number

8

First Page

5627

Last Page

5634

Abstract

Two novel layered compounds BaCuSi2Pn3 (Pn = P, As) adopting new structure types are reported. As revealed by single-crystal X-ray diffraction, both compounds are composed of unique Cu–Si–Pn layers featuring CuPn3 and Si2Pn6 structural motifs found in other archetypal pnictide materials. The stacking of the isostructural Cu–Si–Pn layers is different for phosphide and arsenide compounds. Synthesis from elements aided by in situ synchrotron powder X-ray diffraction resulted in the obtainment of bulk powders with a minimized amount of admixtures. Experimentally measured physical properties of BaCuSi2As3 unexpectedly showed metal-like behavior at temperatures above 15 K, despite the fact that density functional theory calculations predict a small band gap of 0.4 eV. BaCuSi2As3 exhibits ultralow thermal conductivity, which can be explained by the combination of a layered crystal structure with alternating covalent and ionic bonding, which feature rattling of Cu atoms similar to that in tetrahedrites.

DOE Contract Number(s)

AC02-07CH11358; AC02-06CH11357

Language

en

Publisher

Iowa State University Digital Repository, Ames IA (United States)

Available for download on Friday, April 01, 2022

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