# Stabilization of the perovskite phase in the Y-Bi-O system by using a BaBiO$_{3}$ buffer layer

## TL;DR

This study demonstrates that using a BaBiO₃ buffer layer enables stabilization of the perovskite phase in YBiO₃, which is otherwise unstable, by controlling the crystal structure and lattice matching.

## Contribution

The paper introduces a method to stabilize the perovskite phase of YBiO₃ using a BaBiO₃ buffer layer, enabling controlled crystal structure formation.

## Key findings

- BaBiO₃ buffer layer stabilizes perovskite YBiO₃
- Lattice mismatch is mitigated by rocksalt structure formation
- Perovskite structure achieved with proper buffer layer deposition

## Abstract

A topological insulating phase has theoretically been predicted for the thermodynamically unstable perovskite phase of YBiO$_{3}$. Here, it is shown that the crystal structure of the Y-Bi-O system can be controlled by using a BaBiO$_{3}$ buffer layer. The BaBiO$_{3}$ film overcomes the large lattice mismatch of 12% with the SrTiO$_{3}$ substrate by forming a rocksalt structure in between the two perovskite structures. Depositing an YBiO$_{3}$ film directly on a SrTiO$_{3}$ substrate gives a fluorite structure. However, when the Y-Bi-O system is deposited on top of the buffer layer with the correct crystal phase and comparable lattice constant, a single oriented perovskite structure with the expected lattice constants is observed.