Structural and insulator-to-metal phase transition at 50 GPa in GdMnO3

TL;DR

This study investigates the effects of extremely high pressure on GdMnO3, revealing a first-order insulator-to-metal phase transition near 50 GPa characterized by structural change from orthorhombic to cubic.

Contribution

It provides the first detailed high-pressure analysis of GdMnO3, identifying a structural and electronic phase transition using Raman and x-ray diffraction techniques.

Findings

Insulator-to-metal transition occurs near 50 GPa.

Transition involves a change from orthorhombic to cubic structure.

Hysteresis of about 6 GPa indicates first-order transition.

Abstract

We present a study of the effect of very high pressure on the orthorhombic perovskite GdMnO3 by Raman spectroscopy and synchrotron x-ray diffraction up to 53.2 GPa. The experimental results yield a structural and insulator-to-metal phase transition close to 50 GPa, from an orthorhombic to a metrically cubic structure. The phase transition is of first order with a pressure hysteresis of about 6 GPa. The observed behavior under very high pressure might well be a general feature in rare-earth manganites.