Angular dependence of the tunnel magnetoresistance in transition-metal-based junctions

We have investigated the angular behavior of the tunnel magnetoresistance (TMR) in transition-metal-based junctions using the low-field susceptibility of the crossed magnetic configuration. The noncollinear arrangement, stabilized by combining step anisotropy and interfacial exchange-bias coupling, is shown to be of a particular interest for an accurate analysis of the angular dependence of the TMR. We show that the intrinsic tunnel processes are reflected on a linear behavior of the conductivity giving a more complex form for the resistance, as expected by the model of Slonczewski. The more intuitive “high-field” saturating regime deviates the hard layer from its nominal pinning direction and consequently is shown to be less adapted for the experimental study of the intrinsic angular response of the TMR.