Structural and dielectric properties of BaTiO₃/SrTiO₃-multilayers deposited by PLD

Dielectric superlattices are characterized by the structural variability of the film periodicity additional to the stochiometry. They have interesting dielectric properties different from the solid solutions of the same overall composition. In this paper the structural and dielectric properties of BaTiO₃/SrTiO₃-superlattices prepared by pulsed laser deposition on single crystalline substrates are characterized in comparison to a (Ba_0,5Sr_0,5)TiO₃ solid solution. The films were characterized using X-ray diffraction, SEM and dielectric measurements. The BaTiO₃/SrTiO₃-superlattices have a different frequency and a weaker bias and temperature dependence of the dielectric properties than the solid solution. The mechanical stresses caused by the lattice mismatch between the different layers could be one reason for this behaviour.