Surface-acoustic-wave induced ferromagnetic resonance in fe thin films and magnetic field sensing

©2019 American Physical Society R.R. acknowledges financial support through the project MAT2015-66888-C3-3-R (MINECO/FEDER) of the Spanish Ministry of Economy and Competitiveness. The authors thank C. Gourdon and L. Thevenard for fruitful discussions and careful reading of the manuscript. They acknowledge the staff of the MPBT (physical properties-low temperature) platform of Sorbonne University for their support as well as L. Becerra andM. Rosticher for optical and electronic lithography.
Resonant magnetoelastic coupling (MEC) is demonstrated in an Fe thin film epitaxially grown on a piezoelectric GaAs substrate with application of subgigahertz surface acoustic waves (SAWs). The frequency at which resonant MEC is achieved is reduced far below 1 GHz by the application of a small in-plane magnetic field. Moreover, the resonance, observable by attenuation and velocity changes of the SAW, can be switched on and off by a small (0.1 ºC) angular rotation of this in-plane field. This angular sensitivity makes SAW-ferromagnet devices attractive for sensing applications, such as wireless, battery-free, and interrogable magnetic-field monitors. Using a simple magnetization dynamics model that takes into account the Fe magnetic anisotropy and the softening of the magnetic precession modes, we are able to describe the observed salient features.
Ministerio de Economía y Competitividad (MINECO)/FEDER
Depto. de Física de Materiales
Fac. de Ciencias Físicas
TRUE
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