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A. Alberca, M. A. Uribe-Laverde, Y. W. Windsor, M. Ramakrishnan, L. Rettig, I. Marozau, J-M. Tonnerre, J. Stahn, U. Staub, C. Bernhard (2015), Element-specific magnetization redistribution at YBa2Cu3O7/La2/3Ca1/3MnO3 interfaces, in Phys. Rev. B
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Changing materials properties by electric, magnetic and electromagnetic fields lies on the heart of today’s information technologies. In this proposal we like to study the effect of electric fields on the electronic and magnetic properties of magnetic oxides. We will concentrate on magnetic oxides which are magnetoelectric or multiferroic, with the focus on perovskite manganites. For this purpose, we will apply electric fields and study the magnetic and electronic properties on the atomic level of bulk materials and compare it with epitaxial grown films. We will mainly use the reciprocal space technique, resonant x-ray diffraction (RXD), predominantly in the soft x-ray regime. This is a challenging and rapidly developing experimental technique which provides direct access to the magnetic and electronic states of the valence shells of 3d and 4f materials. Our preliminary RXD experiments demonstrate significant changes in the magnetic structure with in-situ applied electric fields of the RMn2O5 multiferroics. In this proposal, investigations are focused on perovskite multiferroic RMnO3 (R=rare earth or Y). We like to extend our current understanding of the orthorhombic materials to the small (heavy) R ions, which cannot be obtained as sufficient sized single crystals. These materials have larger polarization and have recently been shown to be grown as epitaxial films. This allows also to study the strain influence on the magnetic and ferroelectric properties. The main question is to understand the basic interactions of the electric fields with the electronic and the different magnetic properties (structures) of these complex oxides. Such an understanding will be important for future spintronic devices based on the magnetoelectric interaction of multiferroics, in particular in thin films which would be required for future applications.