High-Pressure Tuning of Electrical Transport in Freestanding Oxide Films

TL;DR

This study introduces a new method for high-pressure electrical transport measurements in freestanding oxide films, revealing pressure-induced phase transitions in SrIrO3 and highlighting the role of dimensionality.

Contribution

We developed a universal approach for high-pressure transport measurements in freestanding oxide films and demonstrated its effectiveness with SrIrO3, uncovering pressure-driven phase transitions.

Findings

Pressure induces a semimetal-insulator transition near 2.5 GPa.

An insulator-metal transition occurs around 9 GPa.

Monolayer SrIrO3 remains insulating up to 5.5 GPa.

Abstract

Electrical transport in oxide thin films under high pressure remains largely unexplored due to the lack of a universal experimental strategy. Here we develop an approach that enables high-pressure transport measurements in freestanding oxide films by enhancing their mechanical robustness and integrating them with nanoscale high-pressure devices. As a demonstration, we investigate the resistivity of perovskite SrIrO3 films under hydrostatic pressure and uncover a pressure-driven semimetal-insulator transition near 2.5 GPa, followed by an insulator-metal transition around 9 GPa. In the monolayer limit, SrIrO3 remains insulating and robust against pressure up to 5.5 GPa. The contrasting pressure-dependent phase diagrams of three- and two-dimensional iridates reveal a strong interplay between dimensionality and hydrostatic pressure in correlated oxides. Our work establishes a general platform for exploring pressure-driven phenomena in low-dimensional quantum materials.