Dielectric enhancement of BaTiO3/SrTiO3 superlattices with embedded Ni nanocrystals

The self-organized Ni nanocrystals (NCs) were embedded in BaTiO3/SrTiO3 superlattices using laser molecular beam epitaxy (L-MBE). The stress of the composite films was increased with the increasing concentration of embedded Ni NCs, as investigation in stress calculation. The influence with the various concentrations of Ni NCs embedded in BaTiO3/SrTiO3 superlattices was also discussed. The internal stress of the films was too strong to epitaxial growth of BaTiO3/SrTiO3 superlattices. Compared with the pure BaTiO3/SrTiO3 superlattices, the BaTiO3/SrTiO3 superlattices with lower concentration of embedded Ni NCs had higher permittivity and dielectric loss. Furthermore, the dielectric enhancement of BaTiO3/SrTiO3 superlattices with embedded Ni NCs was proposed to explained by Drude quasi-free-electron theory. (C) 2011 Elsevier B.V. All rights reserved.