Epitaxial growth and thermodynamic stability of SrIrO₃/SrTiO₃ heterostructures

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.