Stabilization of the Perovskite Phase in the Y–Bi–O System By Using a BaBiO₃ Buffer Layer (Phys. Status Solidi RRL 7/2019)

A topological oxide insulator is not yet experimentally observed. However, it is theoretically predicted to exist in the perovskite YBiO3, which paves the way for further investigations into possible topological properties. In article no. 1800679, Rosa Luca Bouwmeester et al. show that by using a BaBiO3 buffer layer, the Y–Bi–O system stabilizes in its thermodynamically unstable perovskite phase instead of in the favorable fluorite structure. On the background of the cover, a high resolution scanning transmission electron microscope image of the interface between the BaBiO3 thin film and SrTiO3 substrate is shown. Here, a rocksalt layer accommodates for the 12% lattice mismatch between the two perovskite structures so that the BaBiO3 film is fully relaxed afterwards.