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DF: Dielektrische Festkörper

DF 7: Poster

DF 7.4: Poster

Donnerstag, 30. März 2000, 09:30–13:00, C

Structural and dielectric properties of BaTiO₃/SrTiO₃-multilayers deposited by PLD — •Köbernik Gerd¹, Hässler Wolfgang¹, and Weiss Francois² — ¹IFW Dresden, PF 270016, 01171 Dresden — ²INPG Grenoble, BP 46, F-38402 St.Martin d’Heres, France

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 and injection MOCVD on single crystalline substrates are characterized in comparison to a Ba_0.5Sr_0.5TiO₃ solid solution. The films were characterized using X-ray diffraction, SEM and dielecric measurements. The BaTiO₃ / SrTiO₃-superlattices have a weaker temperature and frequency 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. We have varied the monolayer thickness of BaTiO₃ and SrTiO₃ and the total film thickness as well, so we could compare the electrical properties like dielectric constant and hysteresis loop of different SrTiO₃/BaTiO₃ multilayers with solid solution films of Ba_0.5Sr_0.5TiO₃ at a wide temperature range from 40K up to 700K.