Effect of electric field on magnetism of ni thin films via antiferromagnetic NiO

Abstract

Effects of electric fields on magnetization of ferromagnetic Ni films grown on a Cu(001) single crystal covered with antiferromagnetic NiO overlayer are investigated by means of X-ray absorption spectroscopy (XAS), X-ray magnetic circular dichroism (XMCD), and magneto-optical Kerr effect (MOKE). The growth of the NiO overlayer on the Ni film is confirmed by XAS, and it is revealed by XMCD and MOKE that the NiO/Ni films show a spin reorientation transition from in-plane to perpendicular magnetization with increasing Ni thickness. It is also observed that the coercive field of the Ni films increases as the NiO thickness increases, possibly due to the interaction with antiferromagnetic NiO. Remanent magnetization of the Ni film is found to be modified by the application of electric fields. The possible origin of the electric-field effects is discussed, and some change in magnetic anisotropy of the Ni film is suggested. [DOI: 10.1380/ejssnt.2018.186]