Epitaxial Growth of (1 1 1)-Oriented Spinel CoCr$_2$O$_4$/Al$_2$O$_3$ Heterostructures

TL;DR

This paper reports the successful epitaxial growth of high-quality (1 1 1)-oriented CoCr₂O₄/Al₂O₃ heterostructures on sapphire substrates, demonstrating a method for creating spinel-based quasi-two-dimensional frustrated lattices through precise layer-by-layer synthesis.

Contribution

It introduces a novel layer-by-layer growth technique for (1 1 1)-oriented spinel heterostructures with confirmed structural and chemical quality.

Findings

High-quality epitaxial heterostructures achieved

Structural and chemical properties verified by multiple techniques

Pathway for fabricating spinel quasi-2D lattices established

Abstract

High quality (1 1 1)-oriented CoCr$_2$O$_4$/Al$_2$O$_3$ heterostructures were synthesized on the sapphire (0 0 0 1) single crystal substrates in a layer-by-layer mode. The structural properties are demonstrated by $in$-$situ$ reflection high energy electron diffraction, atomic force microscopy, X-ray reflectivity and X-ray diffraction. X-ray photoemission spectroscopy confirms that the films possess the proper chemical stoichiometry. This work offers a pathway to fabricating spinel type artificial quasi-two-dimensional frustrated lattices by means of geometrical engineering.