Giant magneto-impedance and stress-impedance effects of microwire composites for sensing applications (original) (raw)
Related papers
2011
The influence of applied stress and the composite geometry on impedance properties of composites containing ferromagnetic microwires has been investigated. The results indicate that the application of tensile stress along the microwire axis and the increase of composite thickness decreased the magneto-impedance (MI) ratio. The stress induced impedance (SI) effect was enhanced with increasing composite thickness reflecting the role of the internal residual stresses. Theoretically calculated matrix-wire interfacial stress from the magneto-impedance profiles is in good agreement with the value of the applied effective tensile stress. This demonstrates a new route to probing the stress conditions of such composites.
Novel magnetic microwires-embedded composites for structural health monitoring applications
Journal of Applied Physics, 2010
We report the results of a systematic study of the magnetic, mechanical, magnetoimpedance and field tunable properties of glass-coated amorphous Co 68.7 Fe 4 Ni 1 B 13 Si 11 Mo 2.3 microwires and composites containing these microwires. The magnetic microwires possess good magnetic and mechanical properties. The magnetoimpedance ratio in the gigahertz range varies sensitively with applied fields below the anisotropy field but becomes unchanged for higher applied fields. The good mechanical properties are retained in the magnetic microwires-embedded composites. The strong field dependences of the effective permittivity and transmission parameters in the gigahertz range indicate that the present composites are very promising candidate materials for structural health monitoring and self-sensing applications.
Ferromagnetic microwires enabled polymer composites for sensing applications
Composites Part A-applied Science and Manufacturing, 2010
In the present work, sensing functionalities are introduced into structural composites via embedded magnetic microwires. A systematic study on the structure and functionalities of microwires and their composites is performed. The single-wire composite shows a significant giant magnetoimpedance (GMI) effect of up to 320% in a frequency range of 1-100 MHz due to stress enhanced transverse magnetoanisotropy. With increasing quantities of embedded wires from 1 to 3, the maximum GMI ratio is enhanced significantly by more than 35%, making the resultant composite favourable for field sensing applications. The microwire-composite also shows superior stress-sensing resolution as high as 134.5 kHz/microstrain, which is about 26 times higher than the recently proposed SRR-based sensor. As evidenced by the structural examination and tensile tests, the extremely small volume fraction of microwires ($0.01 vol.%) allows the wire-composites to retain their mechanical integrity and performance.
Embedded ferromagnetic microwires for monitoring tensile stress in polymeric materials
Composites Part A: Applied Science and Manufacturing, 2014
Considerable efforts have been made to develop testing non-destructive methods for polymer composite materials. We would like to introduce researchers in the field of smart materials to a new method of monitoring internal stresses. The method can be classified as an embedded sensing technique, where the sensing element is a glass-coated ferromagnetic microwire with a specific magnetic anisotropy. With a diameter 10-100 lm, the microwire impedance acts as the controlled parameter which is monitored for a weak alternating current (AC) in the MHz range. The microwire impedance becomes stress sensitive in the presence of a weak constant axial bias magnetic field. This external parameter allows the impedance stress sensitivity to be easily tuned. In addition, a local bias field may also allow the reconstruction of stress profile when it is scanned along the microwire. The experimental results are analysed using simple magnetostatic and impedance models.
Journal of Alloys and Compounds, 2018
The influence of stress-annealing on the magnetic softness and the magnetoimpedance effect of Fe-and Co-based glass-coated microwires is studied. As-prepared Co-rich glass-coated microwires present better magnetic softness and rather higher magnetoimpedance ratio with a double-peak dependence, typical for materials with transverse magnetic anisotropy. As-prepared Fe-based microwires present a rectangular hysteresis loop with a coercivity an order of magnitude higher and a magnetoimpedance ratio of an order of magnitude lower. Stress-annealing of Co-and Fe-based glass-coated microwire allows considerable magnetoimpedance ratio increasing. The impact of stress-annealing is especially pronounced in a Fe-based microwire, where transverse magnetic anisotropy, large (an order of magnitude) improvement of the magnetic softness and magnetoimpedance ratio are observed. In Co-based microwire a magnetoimpedance ratio improvement for short annealing time and a change of hysteresis loop from linear to rectangular are observed. Observed stress-induced anisotropy and related changes of magnetic properties are discussed considering internal stresses relaxation and "backstresses". Obtained experimental results yield new and important insights into the influence of stress-induced magnetic anisotropy on the magnetoimpedance effect and hysteresis loops of glass-coated microwires.
Stress tunable properties of ferromagnetic microwires and their multifunctional composites
Journal of Applied Physics, 2011
We report the results of a systematic study on stress tunable absorption of glass-coated amorphous Co 68.7 Fe 4 Ni 1 B 13 Si 11 Mo 2.3 microwires and their composites. The magnetic microwires possess good stress-impedance properties and yield a stress dependence of absorption at gigahertz frequencies. The stress compensates the reverse effect of magnetic field on absorption. There exist strong stress dependences of the effective permittivity and transmission parameters. Composite failure due to the wire damage results in a dramatic change of the sign and magnitude of effective permittivity. The double peak is identified in the stress dependence of field tunability, in contrast to the single peak for the magnetic field tunability. All these results indicate that the present composites are very promising for detecting the ambient stress levels and interrogating the structural integrity.
Journal of Applied Physics, 2003
The effect of conventional ͑CA͒ and stress annealing ͑SA͒ on magnetic properties of Fe 74 B 13 Si 11 C 2 glass-coated microwires has been studied. CA treatment does not significantly change the character of the hysteresis loop. Under certain annealing conditions ͑annealing temperature, T ann Ͼ300°C, applied stress, Ͼ700 MPa) rectangular hysteresis loop transforms into the inclined with magnetic anisotropy field above 1000 A/m. Such phenomenology has been related to the induction of transverse magnetic anisotropy by SA treatment. Under tensile stress the SA annealed microwire recovers rectangular hysteresis loop. Samples subjected to stress annealing show noticeable magnetoimpedance and stress impedance effects in spite of their large magnetostriction.
Journal of Applied Physics, 2010
We report the results of a systematic study of the magnetic, mechanical, magnetoimpedance and field tunable properties of glass-coated amorphous Co 68.7 Fe 4 Ni 1 B 13 Si 11 Mo 2.3 microwires and composites containing these microwires. The magnetic microwires possess good magnetic and mechanical properties. The magnetoimpedance ratio in the gigahertz range varies sensitively with applied fields below the anisotropy field but becomes unchanged for higher applied fields. The good mechanical properties are retained in the magnetic microwires-embedded composites. The strong field dependences of the effective permittivity and transmission parameters in the gigahertz range indicate that the present composites are very promising candidate materials for structural health monitoring and self-sensing applications.
Influence of geometry on GMI effect of co-based magnetic composite microwires
The influence of varying geometrical factors on the magnetoimpedance (MI) effect in amorphous glass-coated CoFeNiBSiMo microwires has been investigated. The wire geometry and quality of surfaces were deduced from SEM micrographs of the microwires. MI characteristics are influenced by the wire geometry due to metal-glass adhesion, frozen-in stress distribution, and magnetostatic interactions. We found that increasing t results in increase in the coercivity and anisotropy. In the range of frequencies investigated (0.1 -10 MHz), the magnitude of the MI effect may greatly increase as h decreases from 17.40 to 5.33 even if the anisotropy is strongly increased.