Electric field effect on the magnetization process for a very thin Co60Fe40 film

The electric field effect on the magnetization process for a very thin Co60Fe40 film was studied. The magnetization process under the electric field was characterized using tunnel magnetoresistance curves measured in a fully-epitaxial (001)-oriented CoFe(1)/MgO/CoFe(3) (thickness in nanometers) magnetic tunnel junction, where both the CoFe electrodes are magnetized in- plane. The out-of-plane saturation field of the thinner CoFe electrode changed linearly by varying the applied voltage, and the field-induced change of saturation field was estimated to be −0.10 TV−1. This change in the saturation field is interpreted as the electric field induced change in a perpendicular magnetic anisotropy originating from the CoFe/MgO interface. The electric field effect efficiency was estimated to be about 200 fJV−1 m−1.