Dresden 2014 – scientific programme
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DF: Fachverband Dielektrische Festkörper
DF 18: Dielectric and ferroelectric thin films
DF 18.2: Talk
Wednesday, April 2, 2014, 16:20–16:40, GER 37
Correlation between structural and ferroelectric properties of epitaxial PMN-PT films — •Michael Mietschke1,2, Sebastian Fähler1,3, Ludwig Schultz1,2, and Ruben Hühne1 — 1Leibniz-Institut für Festkörper- und Werkstoffforschung, Dresden — 2Technische Universität Dresden — 3Technische Universität Chemnitz
Ferroelectric materials like lead magnesium niobate-lead titanate (PMN-PT) show an electrocaloric effect induced by an electrical field during a diffusionless phase transition, which might be used for novel solid state cooling devices. However, the interplay between the microstructure and the ferroelectric properties is not completely understood so far. To study this in detail, epitaxial 0.68 Pb(Mg1/3Nb2/3)O3-0.32 PbTiO3 films were grown by pulsed laser deposition on (001) single crystalline SrTiO3 (STO) substrates with a miscut angle between 0 and 15 degrees towards the [100] direction. The influences of the deposition parameters and the miscut angle on the PMN-PT structure was studied by x-ray diffraction, atomic force microscopy and scanning electron microscopy. A capacitor like structure was realized by growing the PMN-PT film on a conducting buffer layer with additional Pt-top electrodes on the surface. A nearly pure perovskite phase was found using La0.7Sr0.3Co3 buffer layers on (001) STO substrates and low deposition temperatures. An increasing miscut angle improves the purity of the PMN-PT perovskite phase further. Finally, a correlation of the ferroelectric properties with the phase purity of the PMN-PT film was found.
This work was supported by DFG priority program 1599.