Shear-strain-mediated large nonvolatile tuning of ferromagnetic resonance by an electric field in multiferroic heterostructures

Controlling magnetism by an electric field is of critical importance for the future development of ultralow-power electronic and spintronic devices. Progress has been made in electrically driven nonvolatile tuning of magnetic states in multiferroic heterostructures for the information storage industry, which is exclusively attributed to the ferroelectric-polarization-switching-induced interfacial charge effect or nonlinear lattice strain effect. Here, we demonstrate that a hitherto unappreciated shear strain in the ferroelectric 0.7Pb(Mg1/3Nb2/3)O-3-0.3PbTiO(3) substrate triggered by an electric field can be adopted to obtain robust nonvolatile control of the ferromagnetic resonance in an elastically coupled epitaxial Fe70Rh30 thin film. The disappearance of the resonance peak in a low-field-sweeping mode and the large resonance field shift of 111Oe upon polarization switching demonstrate a strong shear-strain-mediated magnetoelectric coupling effect. In particular, in situ Kerr measurement identifies that the nonvolatile magnetic switching purely originates from electric-field-induced 109 degrees ferroelastic domain switching rather than from 71 degrees /180 degrees ferroelectric domain switching even without the assistance of a magnetic field. This discovery illustrates the role of shear strain in achieving electrically tunable nonvolatile modulation of dynamic magnetic properties, and favors the design of future energy-efficient magnetoelectric microwave devices. Magnetic materials: A strained link between electricity and magnetismA method for electrical control of magnetic materials that takes advantage of physical strain has been developed by scientists in China and Japan. Most computer memories store information in magnetic regions and use magnetic fields to read and write data. Electrical control is more energy efficient, but controlling magnetism with electric fields is difficult. Ming Zheng from the China University of Mining and Technology in Xuzhou, Takamasa Usami and Tomoyasu Taniyama from Nagoya University placed a thin magnetic film on a substrate made of a ferroelectric material. Ferroelectric materials expand or contract when an electric field is applied. This change induces a mechanical strain in the magnetic film and alters its magnetic properties. The team believe that this concept could be extended and applied to future information storage and processing devices. A hitherto unappreciated shear-strain-mediated magnetoelectric coupling effect with highly tunable ferromagnetic resonance by electric field is demonstrated by using the ferroelastic domain engineering of the ferroelectric substrate. The pure shear strain, instead of magnetic field and electric current, control of Kerr signal with superior stability and nonvolatile behaviors shows promising applications in next-generation lightweight, energy efficient magnetoelectric microwave devices and spintronic devices.

Automated summary

A novel method for electrical control of magnetic materials through shear strain-induced magnetoelectric coupling has been demonstrated, showing highly tunable ferromagnetic resonance without the need for magnetic fields or electric currents. This discovery paves the way for energy-efficient magnetoelectric microwave devices in the future.