High real-space resolution measurement of the local structure of Ga_1-xIn_xAs using x-ray diffraction

TL;DR

This study uses high-energy x-ray diffraction to achieve high real-space resolution in atomic pair distribution functions of Ga_1-xIn_xAs alloys, revealing detailed local structural information including bond lengths and strain effects.

Contribution

It provides the first high-resolution real-space measurements of local structure in Ga_1-xIn_xAs, distinguishing bond lengths and analyzing strain broadening effects.

Findings

Resolved Ga-As and In-As bond lengths as a doublet.

Strain broadening is five times larger for distant neighbors.

Results agree with theoretical model calculations.

Abstract

High real-space resolution atomic pair distribution functions (PDF)s from the alloy series Ga_1-xIn_xAs have been obtained using high-energy x-ray diffraction. The first peak in the PDF is resolved as a doublet due to the presence of two nearest neighbor bond lengths, Ga-As and In-As, as previously observed using XAFS. The widths of nearest, and higher, neighbor pairs are analyzed by separating the strain broadening from the thermal motion. The strain broadening is five times larger for distant atomic neighbors as compared to nearest neighbors. The results are in agreement with model calculations.