We study the magnetoimpedance effect, using a Co67Fe4Mo1.5Si16.5B11 amorphous, ribbon-based sensitive element, in the presence of a commercial Ferrofluid® liquid thin layer covering the ribbon surface. The magnetoimpedance response is clearly dependent on the presence of the magnetic ferroliquid, the value of the applied magnetic field, and the parameters of the driving current. The magnetoimpedance-based prototype is proposed as a biosensor with high sensitivity to the fringe field produced by magnetic nanoparticles. A special advantage of this sensor is its high stability to chemical aggressive media; hence, it can be used for in situ measurements during fabrication of biomaterials with a high level of affinity and specificity with nanoparticles employed as bimolecular labels.
The magnetoimpedance effect in several Co-rich amorphous ribbons is overviewed. Results are classified in the following sections: influence of anisotropies induced by stress annealing, dependence on applied stress, its dependence on stress or stress-impedance, and the appearance of hysteresis. The influence of nanocrystallization of given Fe-rich ribbons is also analyzed.
Nanostructured Fe-based alloys have softer magnetic properties, such as larger
saturation polarizations and magnetic permeabilities, smaller anisotropies and
coercive fields and vanishing magnetostrictions, than their precursor alloys in the
amorphous state. The softest magnetic properties are obtained for the smallest
nanocrystalline grain sizes (between 10 and 20 nm), and these nanostructured
materials are very suitable for use as high-frequency electronic components in
magnetic devices or magnetic sensors based on the magnetoimpedance (MI) effect.
In this work we study the correlation between the structural, electrical and
magnetic properties together with the MI effect response in some heat-treated
Finemet type and FeZrB ribbons. We show that the maximum MI ratio of around
130% and a sensitivity to the applied magnetic field of 0.07% (A m−1)−1
is obtained in the heat-treated samples that show an optimum nanocrystalline
state and exhibit softer magnetic properties.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.