Electric-field-control of magnetic anisotropy of Co _0.6Fe _0.2B _0.2/oxide stacks using reduced voltage

We have demonstrated purely electrical manipulation of the magnetic anisotropy of a Co 0.6Fe 0.2B 0.2 film by applying only 8 V across the CoFeB/oxide stack. A clear transition from in-plane to perpendicular anisotropy was observed. The quantitative relationship between interface anisotropy energy and the applied electric-field was determined from the linear voltage dependence of the saturation field. By comparing the dielectric stacks of MgO/Al 2O 3 and MgO/HfO 2/Al 2O 3, enhanced voltage control was also demonstrated, due to the higher dielectric constant of the HfO 2. These results suggest the feasibility of purely electrical control of magnetization with small voltage bias for spintronics applications. © 2012 American Institute of Physics.