Increase in spin injection efficiency of a CoFe∕MgO(100) tunnel spin injector with thermal annealing

R. Wang, X. Jiang, R. M. Shelby, R. M. Macfarlane, S. S. P. Parkin, S. R. Bank, J. S. Harris
2005 Applied Physics Letters  
Postgrowth thermal annealing of a CoFe/ MgO͑100͒ tunnel spin injector grown on a GaAs/ AlGaAs quantum well structure results in a significantly increased spin injection efficiency as inferred from the polarization of heavy-hole electroluminescence from a quantum well optical detector. The as-deposited sample displayed an initial polarization at 100 K of 43%, which was increased to 52% after a 1 h anneal at 300°C, and finally to 55% after a second 1 h anneal at 340°C. The polarization remained
more » ... changed upon further annealing to temperatures as high as 400°C. These results show that tunnel spin injectors based on CoFe/ MgO are robust with high thermal stability, making them useful for device applications.
doi:10.1063/1.1787896 fatcat:xytg4amkbng6pc6rfrbhktnmvi