Strained SrTiO₃/BaTiO₃ Superlattices Formed by Laser Ablation Technique and Their High Dielectric Properties

Abstract

Artificial dielectric superlattices of SrTiO 3 /BaTiO 3 (STO/BTO) have been formed by a pulsed laser ablation technique with in situ monitoring of reflection high-energy electron diffraction (RHEED) oscillation. The superlattices with a stacking periodicity of a few unit cells show higher dielectric constant than that of (Sr 0.5 Ba 0.5 )TiO 3 films with change of temperature or applied frequency. The tetragonal structures of the superlattices are maintained at temperatures of more than 200° C owing to a large stress at the interfaces between STO and BTO layers.