Tunneling spin polarization and annealing of Co72Fe20B8

We present measurements of tunneling spin polarization (TSP) of Co72Fe20B8 alloys in Al/Al2O3/Co72Fe20B8 tunnel junctions to further unravel the role of crystn. of the CoFeB electrodes. Whereas the TSP of films of a few hundred A ngstrom is rather insensitive to anneals up to 500 C , a 50 A film shows a strong redn. of TSP. It is hypothesized that these differences are related to a rather inhomogeneous crystn. of the Co72Fe20B8. Magneto-optical Kerr-effect measurement on 300 A thick CoFeB wedges are used to relate the measured coercivity to these crystn. processes