Regensburg 2004 – wissenschaftliches Programm

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DF: Dielektrische Festkörper

DF 5: Poster

DF 5.1: Poster

Mittwoch, 10. März 2004, 14:30–18:00, Poster C

Well-ordered arrays of ferroelectric BaTiO₃ and SrBi₂Ta₂O₉ nanostructures grown by pulsed laser deposition — •Dietrich Hesse, Wenhui Ma, and Ulrich Gösele — Max-Planck-Institut für Mikrostrukturphysik Halle

Monolayers of monodisperse latex spheres of micron and submicron size were used as deposition masks to fabricate arrays of ferroelectric nanostructures by pulsed laser deposition (PLD). First, arrays of well-ordered BaTiO₃ and SrBi₂Ta₂O₉ amorphous structures were prepared on Nb-doped SrTiO₃ (100) substrates (STO:Nb) by PLD at room temperature. These as-deposited structures were shown to have a pyramid-like shape with lateral sizes between 100 and 200 nm, forming a hexagonal pattern. Post-deposition annealing was used to crystallize these nanostructures. The ferroelectric properties of the crystalline nanostructures were investigated using scanning force microscopy in piezoresponse mode (PFM). Depending on material and size of the nanostructures, piezoelectric hysteresis loops of different shape and size were recorded, demonstrating that BaTiO₃ and SrBi₂Ta₂O₉ nanostructures of 100 to 200 nm lateral size have a remanent polarization and are switchable by an electric field, i.e. they are indeed ferroelectric.