Dresden 2011 – wissenschaftliches Programm

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KR: Fachgruppe Kristallographie

KR 5: Poster Multiferroics (Joint Session of MA, DF, DS, KR, TT)

KR 5.62: Poster

Dienstag, 15. März 2011, 10:45–13:00, P2

Tuning the ferroelectric properties of BiFeO₃ thin films with mechanical stress — •Martin Hoffmann, Oliver Mieth, and Lukas M. Eng — Institut für Angewandte Photophysik, Technische Universität Dresden, D-01062 Dresden

In thin film physics, the crystallographic structure of the deposited film is strongly influenced by the substrate induced strain caused by the lattice mismatch between substrate and film. This leads to the fact that the properties of thin films and surfaces can differ dramatically from the corresponding bulk values.

In the present study, the ferroelectric properties of multiferroic BiFeO₃ thin films on SrTiO₃ under compressive and tensile stress were investigated via piezoresponse force microscopy (PFM). The systematic substrate bending allows us to record the strain dependent domain distribution and the local switching behavior on the nanometer lengthscale. We quantify these effects through monitoring the coercive field and the imprint as a function of applied stress; in fact, we observe that strain effects can be significantly enhanced or even fully compensated in BFO/STO thin films allowing the BFO film to become tunable in its ferroic properties.