Epitaxial growth and thermodynamic stability of SrIrO3/SrTiO3 heterostructures

TL;DR

This study demonstrates optimized growth and encapsulation techniques for high-quality SrIrO3 thin films, enabling detailed transport measurements and device fabrication crucial for exploring exotic quantum phases in 5d transition metal oxides.

Contribution

It introduces a method to improve SrIrO3 film quality via laser target modification and encapsulation with SrTiO3, facilitating advanced transport studies and device fabrication.

Findings

Optimized SrIrO3 film growth by laser target surface modification.

SrTiO3 capping preserves film quality and stability.

Enabling precise transport measurements on nanoscale devices.

Abstract

Obtaining high-quality thin films of 5d transition metal oxides is essential to explore the exotic semimetallic and topological phases predicted to arise from the combination of strong electron correlations and spin-orbit coupling. Here, we show that the transport properties of SrIrO3 thin films, grown by pulsed laser deposition, can be optimized by considering the effect of laser-induced modification of the SrIrO3 target surface. We further demonstrate that bare SrIrO3 thin films are subject to degradation in air and are highly sensitive to lithographic processing. A crystalline SrTiO3 cap layer deposited in-situ is effective in preserving the film quality, allowing us to measure metallic transport behavior in films with thicknesses down to 4 unit cells. In addition, the SrTiO3 encapsulation enables the fabrication of devices such as Hall bars without altering the film properties, allowing precise (magneto)transport measurements on micro- and nanoscale devices.