Magnetically pinned ring dots for spin valve or magnetic tunnel junction memory cells

Abstract Ni–Fe/Mn–Ir asymmetric ring dots with partially planed outer sides are investigated in order to confirm a method for obtaining pinned layers in magnetic memories with asymmetric ring shapes. Magnetic force microscopy revealed that the direction of vortical magnetization is pinned in Ni–Fe/Mn–Ir asymmetric ring dots despite the direction of the magnetic fields. This investigation shows that the Ni–Fe/Mn–Ir asymmetric ring dots can be applied to pinned layers in magnetic memories with asymmetric ring shapes.