SPIN DEPENDENT ELECTRON-TUNNELING BETWEEN FERROMAGNETIC-FILMS

The hysteresis of tunneling resistance in Gd/GdOx/Fe and Fe/GdOx/Fe junctions in the external magnetic field has been observed. The relative changes of tunneling resistance were of order 2.5-7.7%. The domain structures and magnetization reversal processes in the area of tunneling junctions were investigated by defocused electron microscopy. We found that the ferromagnetic coupling between electrodes of the junction strongly modified the domain structures and magnetization reversal processes in the area of tunnel junction. The hysteresis of tunneling resistance was closely connected with magnetization processes in the junction area. We estimated the polarization of tunneling densities of states for Fe electrodes to be not lower than 17% and the change of barrier height corresponding to the barrier spin filtering effect to be of order 1 meV.