The role of the interface in controlling the epitaxial relationship between orthorhombic $\text{LaInO}_\text{3}$ and cubic $\text{BaSnO}_\text{3}$

TL;DR

This study investigates how the interface influences the epitaxial relationship between orthorhombic LaInO3 and cubic BaSnO3, revealing that different domain orientations coexist with similar energies despite strain expectations.

Contribution

The paper combines advanced microscopy, elasticity theory, and density functional calculations to elucidate the role of interfaces in domain orientation stability in LaInO3/BaSnO3 heterostructures.

Findings

Orthorhombic LaInO3 forms three domain types on BaSnO3.

c_{pc} and a_{pc}/b_{pc} domains occur with similar probability.

Density functional theory shows similar energies for different domain orientations.

Abstract

Epitaxial perovskite oxide interfaces with different symmetry of the epitaxial layers have attracted considerable attention due to the emergence of novel behaviors and phenomena. In this paper, we show by aberration corrected transmission electron microscopy that orthorhombic $\text{LaInO}_\text{3}$ films grow in form of three different types of domains on the cubic $\text{BaSnO}_\text{3}$ pseudosubstrate. Quantitative evaluation of our TEM data shows that $c_{pc}$-oriented and $a_{pc}/b_{pc}$-oriented domains are present with similar probability. While continuum elasticity theory suggests that $c_{pc}$-oriented domains should exhibit a significantly higher strain energy density than $a_{pc}/b_{pc}$-oriented domains, density functional calculations confirm that $c_{pc}$- and $a_{pc}$-oriented domains on $\text{BaSnO}_\text{3}$ have similar energies.