TiO2 as an electrostatic template for epitaxial growth of EuO on MgO(001) by reactive molecular beam epitaxy

TL;DR

This study demonstrates that using a TiO2 interfacial layer significantly improves the epitaxial growth quality of EuO on MgO(001) by reactive molecular beam epitaxy, leveraging electrostatic interactions to enhance film quality.

Contribution

It introduces a novel approach employing TiO2 as an electrostatic template to facilitate high-quality EuO epitaxy on MgO(001), with insights into interfacial electrostatic effects.

Findings

TiO2 layer enhances EuO epitaxial growth quality.

Ultrathin EuO films exhibit bulk-like magnetic properties.

Electrostatic interactions influence initial growth modes.

Abstract

We investigate the initial growth modes and the role of interfacial electrostatic interactions of EuO epitaxy on MgO(001) by reactive molecular beam epitaxy. A TiO2 interfacial layer is employed to produce high quality epitaxial growth of EuO on MgO(001) with a 45{\deg} in plane rotation. For comparison, direct deposition of EuO on MgO, without the TiO2 layer shows a much slower time evolution in producing a single crystal film. Conceptual arguments of electrostatic repulsion of like-ions are introduced to explain the increased EuO quality at the interface with the TiO2 layer. It is shown that ultrathin EuO films in the monolayer regime can be produced on the TiO2 surface by substrate-supplied oxidation and that such films have bulk-like magnetic properties.