Ferromagnetic resonance manipulation by electric fields in Ni81Fe19/Bi3.15Nd0.85Ti2.99Mn0.01O12 multiferroic heterostructures.

We investigated electric-field modulation of ferromagnetic resonance (FMR) in Ni81Fe19 (NiFe)/Bi3.15Nd0.85Ti2.99Mn0.01O12 (BNTM) heterostructures at room temperature. BNTM thin films were deposited on a Pt (111)/Ti/SiO2/Si (100) substrate by the sol-gel method. The strain effect is produced by the electric field applied to the BNTM layer, which results in the FMR spectrum shift by tuning of the magnetic anisotropy of the NiFe microstrip devices. A strain-induced magnetic anisotropy change of 332 fJ/Vm is obtained by analyzing the experimental FMR spectra. We discussed an influence on spin orbit torques by applying an electric field to a ferroelectric (FE) layer via coupling to polarization with FMR experiments evidencing. The torque ratios τa/τb increased at first and then declined from the positive to negative electric field. As the value of the applied electric field changes from 129 kV/cm to 0 kV/cm, the variation of the torque ratios τa/τb (the field-like torque τa and damping-like torque τb) is about 0.07. Our results reported in this work demonstrate a route to realize a large magneto-electric coupling effect at room temperature and provide some insights into possible applications of the ferromagnetic/FE device. [ABSTRACT FROM AUTHOR]