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Magneto-optic methods for vectorial magnetometry, Implementation of MO techniques at ICMAB Barcelona

David Hrabovsk - Institut de Ciència de Materials de Barcelona – CSIC, Campus UAB, 08193 Bellaterra, Spain


In this presentation I will describe implementation of magneto-optical techniques at Institute of material science of Barcelona (ICMAB). Developed setups are mainly used to quick characterization of magnetic properties of thin films where magneto-optics brings the possibility to select the desired magnetization component.

In the first part, a short introduction to magneto-optics will be done with the focus on the dependence of MO effect on different components of the magnetization vector. Then I will describe in detail the room temperature MO setup, based on direct differential intensity measurement, and the low temperature setup which use the photoelastic modulator. Then, a detailed study of thin permalloy films exhibiting weak perpendicular anisotropy will be presented.

In the second part I will present the work of our group on multiferroic materials, particularly on hexagonal yttrium manganite (h-YMO). This material shows ferroelectric and antiferromagnetic order at the same time coupled together. In order to explore this functionality and the possibility of controlling ferromagnetism by the electrical field, the heterostructure Py/h-YMO/Pt/(STO) were prepared. In this system - due to interlayer coupling - the change in AF state of YMO layer is reflected in change in Py exchange biasing. At this point I will introduce the concept of exchange bias and a method of transverse susceptibility measurement as a useful tool for exchange coupling measurement. Finally experimental results will be presented.