Analysis of the magnetotransport channels in tunnel junctions with amorphous CoFeB

This work concerns the temperature and bias dependence of the magnetotransport properties of Al oxide-based tunnel junctions with an amorphous Co 60 Fe 20 B 20 soft ferromagnetic electrode and CoFe 10 -based polycrystalline hard electrode. The junctions present high tunnel magnetoresistance of ∼ 50% at room temperature and ∼ 71% at 5 K. A model that takes magnon-assisted inelastic tunneling into account fits satisfactorily the parallel (P) and antiparallel (AP) conductance as a function of temperature. The extracted fitting parameters are then used to reproduce the low-bias anomaly of the P and AP conductance at low temperature.