Current-induced magnetization switching under magnetic field applied along the hard axis in MgO-based magnetic tunnel junctions

The authors have investigated the dependence of the critical current density (Jc) for the current-induced magnetization switching (CIMS) on external magnetic fields applied along the hard axis of a free layer (Hhard) and on the duration of pulse current in MgO-based magnetic tunnel junctions. The Jc and the intrinsic current density (Jc0), derived from the dependence of the Jc on the pulse duration, decreased as ∣Hhard∣ increased. These reductions of Jc and Jc0 would be attributed to the decrease of energy barrier for CIMS and the increase of the spin transfer efficiency.