Spintronics: perspectives for the half-metallic oxides

Due to their total spin polarization (∼100%), the half-metallic oxides, such as La0.7Sr0.3MnO3 (LSMO), CrO2, Fe3O4 and Sr2FeMoO6, are promising materials for producing very high magneto-resistive (MR) responses in magnetic devices. Extremely large MR values have been obtained by tunneling through vertical tunnel junctions, as well as through nano-interfaces or domain walls in planar devices. The state of the art of the spin-polarized half-metallic devices in a two-electrode configuration is described. Moreover, some recent results, that confirm the high spin polarization of these magnetic oxides, are detailed. In case of planar devices, nanofabrication is shown to allow transferring of nanopatterns in a sub-50 nm scale. The technical challenges to integrate these half-metallic oxides devices in the industrial context of magnetic random access memories (MRAMs) are finally discussed. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)