1. Magnetic Tunnel Junctions With $\hbox{Co:TiO}_{2}$ Magnetic Semiconductor Electrodes
- Author
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Lee, Y.J., Abhishek Kumar, A.K., Kumar, A., Vera Marun, I.J., de Jong, Machiel Pieter, and Jansen, R.
- Subjects
Materials science ,EWI-19221 ,Condensed matter physics ,Spintronics ,METIS-279129 ,Doping ,La0.67Sro.33MnO3 ,Magnetic semiconductor ,Cobalt-doped TiO2 ,magnetic tunnel junction ,IR-75549 ,Electronic, Optical and Magnetic Materials ,Paramagnetism ,Tunnel magnetoresistance ,Ferromagnetism ,Charge carrier ,Electrical and Electronic Engineering ,Quantum tunnelling ,magnetic semiconductor - Abstract
Spin-polarized tunneling is investigated in magnetic tunnel junctions containing an ultrathin interfacial layer of Co:TiO2 magnetic semiconductor. The Co:TiO2 layers (0 to 1 nm thick) are inserted at the SrTiO3/Co interface in La0.67Sr0.33MnO3/SrTiO3/Co tunnel junctions. For all junctions we find a negative tunnel magnetoresistance, which decreases upon the insertion of Co:TiO2, while the junction resistance increases strongly. This suggests that the ultrathin Co:TiO2 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.
- Published
- 2010
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