Investigation On The Longitudinal-Driven Asymmetric Giant Magneto-Impedance Effect

GMI effect founded in the last century with high sensitivity at room temperature and under the weak magnetic field, its coming as new physical effect the development of new magnetic sensor of the most competitive and development prospects.The basic characteristics of GMI is that, its impedance presented symmetry varies with the magnetic field in zero magnetic field and the sensitivity is low. Asymmetric giant magneto-impedance effect (Asymmetric giant magneto-impedance AGMI effect) could meet the giant magneto-impedance at weak magnetic fields in the vicinity of high linearity and sensitivity. Therefore, this article based on the characteristics of GMI effect to study the properties of asymmetric GMI effect of driving under the portrait mode, which is important for the development of a new type of magnetic sensor.We choose Fe73.5Cu1Nb3Si13.5B9alloy which has the classic components, we studied the high current and high temperature annealing crystallization on the sample, the AGMI characteristics were measured by longitudinal drive mode, the specific research results are as follows:1.Large current annealing and beyond crystallization of high temperature annealing on AGMI effect of the sample:(1)Obtained the AGMI effect with ratio of42.02%at annealing current density of59.2A/mm2, the AGMI ratio increase slightly after magneticed by longitudinal magnetic field.(2)At630℃temperature annealing10min, we obtained the AGMI effect with ratio of155.60%, with the increase of annealing temperature, sample’s AGMI ratio decreases gradually.2.AGMI effect of composite structure sample:(1)An amorphous sample with the sample with AGMI effect after a simple superposition of the same size composite, the composite strip around the magnetization showed no significant effect of AGMI, even if the sample has a single effect superimposed AGMI amorphous sample both ends did not appear AGMI phenomenon, but with the increase in superimposed layers, complex arithmetic with GMI ratio showed a similar law of diminishing.(2)Wide linear sample with the annealed samples produced AGMI effect of the same size after a simple superposition compound, along with a longitudinal magnetic field of composite magnetic response interval in-744A/m to the279A/m, sensitivity up to0.65%/(A/m), a linearity of0.99896, and no hysteresis AGMI characteristics. The way that the sample is superimposed with the effect AGMI ends GMI samples having a wide linear characteristic only after the magnetizing magnetic field, it appears AGMI composite effect with zero magnetic field.3.The X-ray diffraction analysis the samples and the average grain size of the phase composition analysis found:(1)According to XRD analysis of the data obtained, B6Fe23hard magnetic phase appears after annealing the sample in a large current is cause AGMI effects.(2)With the hard magnetic phase of the composite with a soft tape play a role in the bias field and magnetic field after magnetization can enhance the effect of the bias field.These results obtained with soft magnetic crystalline compound with a wide linear characteristics of soft magnetic tape containing the hard magnetic phase with composition can be both hard magnetic tape containing the soft phase of the zero-field non-linear symmetry and soft grain belt width high sensitivity, enabling rapid and sensitive response near zero magnetic field. This is a novel approach to the use of vertical drive cross-sensitivity response of the zero-field method has great significance for the design and application of new magnetic sensors.