Regensburg 2016 – scientific programme

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DF: Fachverband Dielektrische Festkörper

DF 11: Poster

DF 11.22: Poster

Wednesday, March 9, 2016, 18:00–20:00, Poster E

Piezoresponse force microscopy of domain wall motion in thin film ferroelectrics — •Robert Roth¹, Er-Jia Guo^1,2, Martin Koch¹, Kathrin Dörr¹, and Thomas Thurn-Albrecht¹ — ¹Martin Luther University Halle-Wittenberg, Institute of Physics, 06099 Halle, Germany — ²Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA

Ferroelectric domain wall motion is often studied in an atomic force microscope (AFM) by writing ferroelectric domains under a conductive voltage-biased AFM tip and subsequent imaging by recording the local piezoresponse signal [1]. Next to the writing voltage and time, parameters like temperature, ambient atmosphere and elastic strain [2] strongly influence the domain growth and the stability of grown remanent domains. We show results on domain stability and velocity of 180^∘ domain walls in a 24 nm thick epitaxial BaTiO₃ (BTO) film. BTO is a strong candidate material for the ferroelectric tunnel barrier in multiferroic tunnel junction devices, but its domain dynamics in thin epitaxial films is yet rarely investigated. As second example, domain growth in a prototype ferroelectric polymer, polyvinylidene fluoride trifluoroethylene (PVDF-TrFE 70/30) has been studied. A strong impact of microstructure parameters such as the orientation and the thickness of the polymer lamellae on domain wall velocity has been observed. These microstructure parameters have been controlled to some degree by the choice of substrate and an optimized annealing procedure.

[1] T. Tybell et al., Phys. Rev. Lett. 89, 097601 (2002), [2] E.-J. Guo, R. Roth, et al., Adv. Mater. 27, 1615 (2015)