Selective growth of Ruddlesden-Popper strontium iridate epitaxial films by controlling oxygen partial pressure in pulsed laser deposition

Abstract

The Ruddlesden-Popper (RP)-type strontium iridate (SrIrO3 and Sr2IrO4) epitaxial thin films are selectively grown from a single Sr2IrO4 target using pulsed laser deposition. The stabilization of the SrIrO3 and Sr2IrO4 phase is sensitive to oxygen partial pressure (PO2). Low laser fluence tends to expand the growth window of pure Sr2IrO4 films. The lower PO2 (≤2.6Pa) is preferred for preparing Sr2IrO4 films, while the SrIrO3 phase forms at higher PO2 (≥6.5Pa). The growth diagram for SrIrO3 and Sr2IrO4 films has been summarized, providing a powerful guideline for fabricating the epitaxial films of single RP-type strontium iridate phase.