arXiv subjects

Johan Moulin

Publications and source records attributed to Johan Moulin.

3 recordsLinked to original sources

arXiv2014

Combining ferromagnetic resonator and digital image correlation to study the strain induced resonance tunability in magnetoelectric heterostructures

This paper reports the development of a methodology combining microstrip ferromagnetic resonance (MS-FMR) and digital image correlation (DIC) in order to silmuteanously measure the voltage-induced strains and the magnetic resonance in artificial magnetoelectric heterostructures (magnetic films/piezoelectric substrate? or magnetic films/flexible substrate/piezoelectric actuator ?). The overall principle of the technique and the related analytical modelling are described. It is powerful to estimate the magnetostriction coefficient of ferromagnetic thin films and can be used to determine the effective magnetoelectric coefficient of the whole heterostructures in addition to the piezoelectric coefficient related to the in-plane voltage-induced strains. This methodology can be applied to system for which the strains are well transmitted at the different interfaces.

cond-mat.mtrl-sci↗

arXiv2014

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

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 $(λ=16\times10^{-6}$) and consistent with the usually reported values for bulk amorphous FeCuNbSiB.

cond-mat.mtrl-sci↗

arXiv2014

Magnetic domain-wall motion study under an electric field in a Finemet thin film on flexible substrate

Influence of applied in-plane elastic strains on the static magnetic configuration of a 530 nm magnetostrictive FeCuNbSiB thin film. The in-plane strains are induced via the application of a voltage to a piezoelectric actuator on which the film/substrate system was glued. A quantitative characterization of the voltage dependence of the induced-strain at the surface of the film was performed using a digital image correlation technique. MFM images at remanence (H=0 Oe and U=0 V) clearly reveal the presence of weak stripe domains. The effect of the voltage-induced strain shows the existence of a threshold value above, which the break of the stripe configuration set in. For a maximum strain of exx~0.5*10-3 we succeed in destabilizing the stripes configuration helping the setting up of a complete homogeneous magnetic pattern.

cond-mat.mtrl-sci↗