Observation of Stress Assisted Magnetization Reversal in a Spin Valve Structure

In order to reduce a power consumption of a perpendicular magnetoresistive random access memory, a stress assisted magnetization reversal method in which an in-plane tensile stress changes the magnetic anisotropy of a magnetic material has been proposed. A spin valve structured giant magnetoresistive multilayer of Cu(15 nm)/Terfenol-D(10 nm)/Cu(3 nm)/Tb-Fe-Co(30 nm)/Cu(15 nm) was prepared and its perpendicular magnetization was measured by the anomalous Hall effect. When a mechanical stress of 279 MPa was applied to the multilayer, a direction of the magnetization of only the free layer, a recording layer, was changed from perpendicular to in-plane.