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

Abstract

Artificial dielectric superlattices of SrTiO3/BaTiO3 (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 (Sr0.5Ba0.5)TiO3 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.