Pressure-Induced Insulating State in Ba1-xRExIrO3 (RE = Gd, Eu) Single Crystals

TL;DR

This study reveals that applying pressure to Ba1-xRExIrO3 single crystals induces a transition from a metallic to an insulating state, highlighting a complex interplay between structural and electronic factors.

Contribution

It demonstrates a rare pressure-induced insulating state in BaIrO3, contrasting with doping effects, and uncovers the delicate balance of structural and electronic interactions.

Findings

Pressure restores insulating behavior with a three-order magnitude increase in resistivity.

Light RE doping induces metallicity, but pressure reverses this to insulator.

The response to pressure and doping indicates a complex interplay of structural and electronic degrees of freedom.

Abstract

BaIrO3 is a novel insulator with coexistent weak ferromagnetism, charge and spin density wave. Dilute RE doping for Ba induces a metallic state, whereas application of modest pressure readily restores an insulating state characterized by a three-order-of-magnitude increase of resistivity. Since pressure generally increases orbital overlap and broadens energy bands, a pressure-induced insulating state is not commonplace. The profoundly dissimilar responses of the ground state to light doping and low hydrostatic pressures signal an unusual, delicate interplay between structural and electronic degrees of freedom in BaIrO3.