Epitaxial Sr-doped nickelate perovskite thin films and Ruddlesden-Popper phases grown by magnetron sputtering

TL;DR

This paper demonstrates the successful epitaxial growth of Sr-doped nickelate perovskite and Ruddlesden-Popper phases using RF magnetron sputtering, providing insights into their stability and properties for scalable thin film production.

Contribution

It introduces a novel RF magnetron sputtering method for stabilizing epitaxial nickelate phases, overcoming previous challenges associated with oxidation states and structural defects.

Findings

Epitaxial NSNO films were successfully grown on SrTiO3 substrates.

The thermal stability of the perovskite phase was characterized.

Structural and electronic properties of RP phase films were analyzed.

Abstract

Sr-doped nickelate, Nd1-xSrxNiO3 (NSNO), perovskite thin films and Ruddlesden-Popper (RP) phases are actively investigated because of their physical properties, such as the metal-insulator transition and superconductivity. However, achieving epitaxial growth of NSNO perovskite and RP phase films in a sputtering system is challenging compared to pulsed laser deposition and molecular beam epitaxy, due to the difficulty in stabilizing nickel oxidation states and minimizing structural defects. Here, we used an off-axis radio frequency (RF) magnetron sputtering to fabricate epitaxial NSNO perovskite and RP phase thin films on SrTiO3 (001) substrates, systematically controlling the growth temperatures. We investigated the thermal stability of the perovskite phase and the structural and electronic characteristics of the RP phase films. These findings provide valuable insights into the synthesis of nickelate RP phase films using RF magnetron sputtering, paving the way for scalable thin films fabrication technologies.