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DF: Dielektrische Festkörper

DF 6: Poster

DF 6.13: Poster

Mittwoch, 28. März 2001, 14:30–18:00, Foyer S3

Preparation of ferroelectric BaTiO₃ nanostructures on vicinal Nb-doped SrTiO₃ substrates — •Alina Visinoiu, Marin Alexe, Ho Nyoung Lee, Alain Pignolet, Dietrich Hesse, and Ulrich Gösele — Max-Planck-Institut für Mikrostrukturphysik, Halle, Germany

Size effects of ferroelectric materials are of considerable scientific and technological interest and have attracted attention because of potential applications of ferroelectric materials in microelectronic devices. Ferroelectric BaTiO₃ (BTO) thin films and nanostructures with lateral sizes below 100 nm have been deposited by pulsed laser deposition (PLD) onto (100)-oriented Nb-doped SrTiO₃ (Nb:STO) substrates. In order to grow BTO nanostructures, vicinal substrates with different miscut angles have been treated by etching in buffered HF and annealing at high temperature (1200 ^∘C). The effect of different chemical treatments and thermal annealing on STO surfaces was analyzed by atomic force microscopy (AFM) working in tapping mode. Growth mechanisms of BTO nanostructures on STO substrates were also investigated by AFM. Under certain deposition conditions, the BTO growth mode changes from layer-by-layer to island growth leading to the formation of BTO structures 0.8 to 2.7 nm high and 30 to 60 nm wide. The influence of different miscut angles of the Nb:STO (100) substrates on the growth mechanism of BTO nanostructures will be presented. The electric properties of BTO on Nb:STO vicinal substrates are under investigation by piezoelectric and switching measurements performed using an AFM working in piezoresponse mode.