Experimentally tailoring s-d and p-d interactions in spin polarization via post deposition annealing conditions

We investigated magneto-electrical properties and the effect of intrinsic point defects in the lattice on film properties of 10 mol% cobalt containing ZnO thin films that were doped with 0.7 +/- 0.1 to 1.1 +/- 0.2 mol% W atoms. Thin films were deposited on Si (100) substrates. The anomalous Hall Effect seen in magneto-electrical measurements indicated a correlation between the polarized spins and the positive magneto-resistivity due to hole and electron mediated interactions. N-type carriers were dominant in conductivity, as shown by Hall resistance measurements. The 55 % positive magneto-resistivity and the split of 132.3 +/- 0.1 Omega and 28.5 +/- 0.1 Omega differences in the magneto-hysteresis curves through both negative and positive regions, respectively, proved that a polarized spin current was effectively formed under both s-d and p-d interactions. In addition, the shallow energy levels, close to extreme points of conduction and valance bands, reinforced the polarized spin current. (C) 2015 Elsevier B.V. All rights reserved.