Electric field induced non-90° rotation of the easy axis of a ferromagnetic film

• Published in: Applied physics letters 2018-01, Vol.112 (5)
• Main Authors: Guo, Zhe, Yang, Xiaofei, Liu, Xiangli, Ou-Yang, Jun, Zhu, Benpeng, Chen, Shi, Zhang, Yue
• Format: Article
• Language: English
• Subjects: Applied physics; Electric fields; Ferromagnetic materials; Heterostructures; Hysteresis loops; Magnetic anisotropy; Magnetic fields; Magnetic films; Magnetoresistance; Magnetoresistivity; Rotation; Stability; Thin films
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.5005049

We report that an electric field can induce a non-90° rotation of an in-plane easy axis of a magnetic thin film. Based on the magnetic hysteresis loop measurements for a FeCoSiB/0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 multiferroic heterostructure, we found that when an electric field induced uniaxial anisotropy field HK1 is generated in a magnetic film with an initial uniaxial anisotropy field HK2, and there is a non-90° angle between these fields, the combination of these two fields effectively rotates HK2 by a non-90° angle. Based on the measurement of anisotropic magnetoresistance, one can see that the non-90° rotation of the easy axis changes the direction of the magnetic field for observing the maximum and minimum magnetoresistance. The mechanism for this non-90° rotation of the easy axis was discussed using the theory of magnetic anisotropy. This research paves a way for the development of magnetic sensors with an ability to control the direction of the measured magnetic field by using an external electric field.