Local structure of ReO$_3$ at ambient pressure from neutron total scattering study

TL;DR

This study uses neutron total scattering to investigate whether local ReO$_6$ octahedral rotations exist in ambient-pressure ReO$_3$, finding no evidence for such rotations and confirming the average structure.

Contribution

It provides the first detailed neutron scattering analysis confirming the absence of local octahedral rotations in ambient ReO$_3$, aligning local and average structures.

Findings

No evidence for large local octahedral rotations.

Local and average structures are the same (Pm$ar{3}$m).

Supports the assumption of a untilted ambient phase.

Abstract

A hypothesis that the local rotations of ReO$_6$ octahedra persist in the crystallographically untilted ambient phase of ReO$_3$ is examined by the high-resolution neutron time-of-flight total scattering based atomic pair distribution function analysis. Three candidate models were tested, Pm$\bar{3}$m, P4/mbm, and Im$\bar{3}$, for the local structure of ReO$_3$ at ambient pressure and 12 K, and both quantitative and qualitative assessment of the data were performed. No evidence for large local octahedral rotations was found, suggesting that the local and the average structure are the same (Pm$\bar{3}$m) as normally assumed.