Publication Date

3-16-2018

Department

Ames Laboratory; Chemistry

Campus Units

Chemistry, Ames Laboratory

Report Number

IS-J 9640

DOI

10.1021/acs.inorgchem.8b00214

Journal Title

Inorganic Chemistry

Volume Number

57

Issue Number

7

First Page

4039

Last Page

4049

Abstract

Using density functional theory, the crystal structure variation of AAuAl (A = Ca, Sc, and Ti) from orthorhombic Co2Si-type to distorted hexagonal Fe2P-type and then Ni2In-type structures is shown to correlate with their electronic struc-tures and valence electron counts, sizes of the active metals A, and site preferences for Au and Al atoms, which are arranged to maximize Au−Al nearest neighbor contacts. An evaluation of chemical pressure imposed by the varying A metals using total energy vs. volume calculations indicates that larger unit cell volumes favor the orthorhombic structure whereas smaller vol-umes favor the hexagonal structures. The electronic origin of the Mg2Ga-type crystal structure of ScAuAl, refined as a distorted Fe2P-type supercell doubled along the c-axis, indicates a Peierls-type distortion mechanism of the Au-chains along the c-axis.

Language

en

Department of Energy Subject Categories

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Publisher

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

Available for download on Saturday, March 16, 2019

Share

COinS