Development of multiferroic tunnel junctions: structure, magnetic and transport properties of ferromagnetic/ferroelectric multilayers

L. AVILES FELIX, S. CARREIRA, F. FERNANDEZ BALDIS, E. KAUL, M. SIRENA, L.B. STEREN, J. LESUEUR, N. BERGEAL, R. BERNARD, J. BRIATICO, G. FAINI, J. VILLEGAS

Boston

Conferencia; Material Research Society, Fall Meeting; 2011

Material Resesarch Society

Ferromagnetic/ferroelectric (FM/FE) bilayers, trilayers and superlattices were grown by DC sputtering. X-ray diffraction indicates that the samples present a textured growth with the c axis perpendicular to the substrate. Magnetization measurements show  that the ferromagnetic layers are weakly coupled, probably due to magnetostatic interactions. A phenomenological approach is proposed to analyze the electrical transport in the FM/FE bilayer systems, measured by conductive atomic force microscopy. The influence of the substrate in the electrical properties of the bilayers was studied in the frame of this model. Substrate roughness was found to increase the barrier height distribution and increase the attenuation length in the material, reducing the barrier quality. Lithography based microtemplates were developed for the fabrication of multifferoic tunnel junctions.