Growth mode mapping and structural properties of controlled perovskite BaTiO₃/SrTiO₃heterostructure

Abstract

Perovskite heteroepitaxy was investigated under various conditions using laser molecular beam epitaxy. Well-controlled BaTiO₃/SrTiO₃ heterostructure was studied with in situ reflective high energy electron diffraction and ex situ atomic force microscopy, x-ray diffraction, and transmission electron microscopy. The growth mode map of BaTiO₃ thin films was obtained as a function of substrate temperature under 600 °C for various laser repetition rates. The effective activation energy of surface migration was determined to be 0.33 eV. A mechanism of surface migration in BaTiO₃ heteroepitaxy was described for a basic understanding of atomic-scale controlled preparation of ferroelectric heterostructures at low temperature.