Computer simulation of coherent BaZrO3/MgO interfaces

Abstract

A combination of empirical potential and first-principles modeling techniques is used to probe the structures and energetics of BaZrO3(001)/MgO(001) heterointerfaces in superconducting thin film substrates. The small misfit of ∼0.5% between the component lattices results in a coherent interface of low excess energy and high stability when the BaZrO3 crystal is terminated by a ZrO2 layer. The interface energy is calculated to be about 0.5 J m−2. The stable interface structure consists of O ions in the ZrO2 layer situated above Mg ions, and O ions in the MgO layer adjacent to Zr ions. The band gap at the interface is noticeably less than that of single-crystal BaZrO3, suggesting that it should be possible to design novel semiconducting/optoelectronic oxide materials at the nanoscale using thin film technology.