Magnetization process of a ferromagnetic nanostrip under the influence of a surface acoustic wave

David Castilla, Rocío Yanes, Miguel Sinusía, Gonzalo Fuentes, Javier Grandal, Marco Maicas, Tomás E. G. Álvarez-Arenas, Manuel Muñoz, Luis Torres, Luis López & José L. Prieto
Sci Rep 10, 9413 (2020)

Surface Acoustic Waves (SAW) are one of the possible solutions to target the challenges faced by modern spintronic devices. The stress carried by the SAW can decrease the current required to achieve magnetic switching or domain wall movement by spin transfer torque. Although the last decade has produced very relevant results in this field, it is still important to study the effects of a SAW on the basic unit of many spintronic devices, a ferromagnetic nanostrip. In this work, we perform a complete set of measurements and simulations to characterize the magnetization process of a Ni nanostrip under the influence of a SAW. We find that the SAW increases the mobility and the depinning ability of the magnetic domain walls and consequently, promotes a sharper approach to saturation and substantially decreases coercivity. We have also found other two interesting effects. When the SAW has sufficient energy, is able to trigger irreversible transitions even before switching the direction of the external magnetic field. Additionally, we have found that the magnetization process depends on the direction of the travelling SAW.

Acknowledgements

We acknowledge the support from projects MAT2017-87072-C4-1-P, MAT2017-87072-C4-4-P and MAT2017-87072-C4-3-P from the Spanish government and project SA299P18 from the Junta de Castilla y Leon.