Growth of strontium ruthenate films by hybrid molecular beam epitaxy

TL;DR

This paper demonstrates a hybrid molecular beam epitaxy method for growing high-quality epitaxial Sr2RuO4 films using a volatile RuO4 precursor, enabling better control and opening avenues for complex oxide research.

Contribution

Introduction of a hybrid MBE technique utilizing RuO4 precursor for improved growth of epitaxial Sr2RuO4 films, overcoming limitations of traditional methods.

Findings

Achieved phase-pure, epitaxial Sr2RuO4 films.

Observed layer-by-layer growth mode at high temperatures.

Films exhibit high structural quality confirmed by multiple microscopy techniques.

Abstract

We report on the growth of epitaxial Sr2RuO4 films using a hybrid molecular beam epitaxy approach in which a volatile precursor containing RuO4 is used to supply ruthenium and oxygen. The use of the precursor overcomes a number of issues encountered in traditional MBE that uses elemental metal sources. Phase-pure, epitaxial thin films of Sr2RuO4 are obtained. At high substrate temperatures, growth proceeds in a layer-by-layer mode with intensity oscillations observed in reflection high-energy electron diffraction. Films are of high structural quality, as documented by x-ray diffraction, atomic force microscopy, and transmission electron microscopy. The method should be suitable for the growth of other complex oxides containing ruthenium, opening up opportunities to investigate thin films that host rich exotic ground states.