Micro-strip ferromagnetic resonance study of strain-induced anisotropy in amorphous FeCuNbSiB film on flexible substrate

TL;DR

This study demonstrates how strain induced by a piezoelectric actuator can control magnetic anisotropy in a flexible amorphous FeCuNbSiB film, using micro-strip ferromagnetic resonance and elastic strain measurements.

Contribution

It introduces a method to control magnetic anisotropy via strain in a flexible substrate and models the magnetostrictive response considering elastic properties.

Findings

Magnetic anisotropy can be tuned with small voltages applied to the actuator.

The magnetostrictive coefficient was measured as positive, λ=16×10^{-6}.

Elastic strains effectively transmit through the flexible substrate.

Abstract

The magnetic anisotropy of a FeCuNbSiB (Finemet) film deposited on Kapton has been studied by micro-strip ferromagnetic resonance technique. We have shown that the flexibility of the substrate allows a good transmission of elastic strains generated by a piezoelectric actuator. Following the resonance field angular dependence, we also demonstrate the possibility of controlling the magnetic anisotropy of the film by applying relatively small voltages to the actuator. Moreover, a suitable model taking into account the effective elastic strains measured by digital image correlation and the effective elastic coefficients measured by Brillouin light scattering, allowed to deduce the magnetostrictive coefficient. This latter was found to be positive $(\lambda=16\times10^{-6}$) and consistent with the usually reported values for bulk amorphous FeCuNbSiB.