Magnetic Tunnel Junctions With Co:TiO Magnetic Semiconductor Electrodes
نویسندگان
چکیده
Spin-polarized tunneling is investigated in magnetic tunnel junctions containing an ultrathin interfacial layer of Co:TiO magnetic semiconductor. The Co:TiO layers (0 to 1 nm thick) are inserted at the SrTiO Co interface in La Sr MnO SrTiO Co tunnel junctions. For all junctions we find a negative tunnel magnetoresistance, which decreases upon the insertion of Co:TiO , while the junction resistance increases strongly. This suggests that the ultrathin Co:TiO is a paramagnetic insulator that acts as an additional tunnel barrier, in contrast to thick (180 nm) layers grown under comparable conditions, which exhibit metallic impurity band conduction and room-temperature ferromagnetism.
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