Dresden 2017 – scientific programme

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DF: Fachverband Dielektrische Festkörper

DF 15: Ferroics - Domains, Domain Walls and Skyrmions III

DF 15.5: Talk

Wednesday, March 22, 2017, 16:30–16:45, WIL B321

A numerical approach to optical second harmonic generation imaging of multiferroic domains — •Thomas Lottermoser, Christoph Wetli, Amadé Bortis, and Manfred Fiebig — Department of Materials, ETH Zürich, Zürich, Switzerland

Due to its direct coupling to symmetry optical second harmonic generation (SHG) has been established as a versatile tool for the investigation of magnetoelectric multiferroics. As the only method it allows a non-invasive and simultaneous access to both, the electric and magnetic order of a multiferroic in a single experiment. It not only gives access to the often complex and interlinked interactions of the related order parameters on a macroscopic level, but also spatially resolved on the level of domains. Nevertheless, as any optical imaging method also SHG imaging is limited by the optical resolution of about one micron. Here we present a numerical model based on a statistical analysis of the domain imaging to overcome this limitation and to reveal information of the domain topology and their size distribution even several orders of magnitude below the resolution limit. The model is tested numerically against different domain topologies like the well known antiferromagnetic and ferroelectric domain structures that occur in the multiferroic hexagonal manganites. We can distinguish these different structures by the respective intensity of the SHG response, even if their domains are of equal lateral size.