Dresden 2017 – wissenschaftliches Programm
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DF: Fachverband Dielektrische Festkörper
DF 11: Ferroics - Domains, Domain Walls and Skyrmions II
DF 11.4: Vortrag
Mittwoch, 22. März 2017, 10:45–11:00, WIL B321
Domain wall architecture in tetragonal ferroelectric thin films — •Gabriele De Luca1, Marta D. Rossell2, Jakob Schaab1, Nathalie Viart3, Manfred Fiebig1, and Morgan Trassin1 — 1Department of Materials, ETH Zurich, Switzerland — 2Electron Microscopy Center, EMPA, Switzerland — 3Institut de Physique et Chimie des Matériaux de Strasbourg, France
Ferroic domain walls separate regions with a different orientation of the order parameter. The resulting lowering of the local symmetry enables properties that are otherwise not allowed in the bulk rendering them attractive for potential applications. Lead Zirconate Titanate (PZT) is the most important ferroelectric material to date, and its performance largely depends on the behaviour of its domains and domain walls. For example, in PZT thin films, out-of-plane-polarized c-domains are typically interspersed by in-plane-polarized a-domains that obstructs the controlled migration of 180∘ domain walls due to pinning at surface dislocations. Combining scanning transmission electron microscopy and nonlinear optics we determine the relation between strain, film thickness, local electric fields and the resulting domain and domain-wall structure across the entire thickness of various PZT films [1]. We find that the voltage-induced c-domain walls are inclined and exhibit a mixed Ising-Néel-type rotation of polarization across the wall with a specific nonlinear optical response. The domain wall tilt leads to a macroscopic tail-to-tail polarization component where accumulation of screening charges can be expected.
G. De Luca et al., Adv. Mater. 28 (2016)