engleski

Functional Oxide Nanostructures and Heterostructures for Spintronics

Due to the large diversity of their physical properties and the potentiality to modulate them, the role of oxides in electronics has continuously increased over the past few years. The field of spintronics is no exception. This functional character is further increased by the possibility to obtain radically new properties at their interfaces. To illustrate our work in this field, we will present the results on all manganite tunnel junctions in which ferromagnetism is induced in the barrier by proximity effect resulting in a related exchange splitting of the conduction band and the ensuing spin filtering phenomena. Also, the experiments on heterostructures combining ferroelectric tunnel barriers of BaTiO3 and ferromagnetic electrodes (Fe or Co) will be discussed. This kind of heterostructures allows to generate, within a single device, not only a tunnel magnetoresistance (TMR) phenomena related to the relative orientation of the magnetization of the electrodes and a tunnel electroresistance (TER) induced by the ferroelectric polarisation of the barrier. They also give rise to an interfacial magnetoelectric coupling that results in an unusual modulation of the spin polarisation at the interface by the ferroelectricity resulting in a TEMR (Tunnel Electro MagnetoResistance) effect in these artificial multiferroic heterostructures. Finally, we will show the recent results on the conduction at the interface between two insulating materials SrTiO3 and LaAlO3 and the experiments we have performed in order to determine the extension of this electron gas.

spintronics; manganites; multiferroics; STO diluted oxides

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