Sub-unit cell engineering of CrVO$_3$ superlattice thin films

TL;DR

This paper demonstrates the layer-by-layer fabrication of CrVO$_3$ superlattice thin films with atomic precision, stabilizing the ilmenite phase and exploring their properties, thus enabling new complex oxide materials with customizable functionalities.

Contribution

It introduces a novel method for growing ordered corundum oxide superlattices with atomic-scale control, including stabilization of the ilmenite phase of CrVO$_3$.

Findings

Successful stabilization of ilmenite phase of CrVO$_3$

Atomic-scale control of superlattice layer thickness

Comparison of experimental and theoretical properties

Abstract

Ordered corundum oxides introduce new prospects in the field of functional oxides thin films, complementing the more widely studied class of ABO$_3$ perovskites. In this work, we take advantage of the layer-by-layer growth regime to fabricate epitaxial CrVO$_3$ superlattice thin films with atomic-scale accuracy on the periodic arrangement of Cr and V layers. By means of X-ray diffraction, scanning transmission electron microscopy and Raman spectroscopy, we confirm the thickness control in the sub-unit cell scale, alternating 3, 2 or 1 single atomic layers of Cr$_2$O$_3$ and V$_2$O$_3$. For the first time, we stabilize the ilmenite phase of CrVO$_3$ (space group R-3) and compare the functional properties of the thin film with those calculated by density functional theory. This novel approach to the growth of ordered corundum oxides opens the path towards the stabilization of new complex oxides with tailored properties by varying the composition and the superlattice period, ultimately broadening the family of functional rhombohedral oxides.