The frequency dependence of magnetization process and giant magneto impedance （GMI） effect of Co-rich melt-extracted amorphous wires was studied by Kerr effect and impedance analyzer, respectively. It is demonstrate...The frequency dependence of magnetization process and giant magneto impedance （GMI） effect of Co-rich melt-extracted amorphous wires was studied by Kerr effect and impedance analyzer, respectively. It is demonstrated that the transverse Kerr intensity and the corresponding GMI response increase with increasing frequency, which contributes to the upgraded skin effect. However, the skin depth has a slothful trend with frequency when it is up to the megahertz range, which gives rise to the transformation of magnetization. The process is much more sensitive to the direct current magnetic field and the sensitive change of the circular permeability, and GMI response is observed as its consequence. This proves that the evolution of circumferential magnetization and the corresponding permeability with the direct current magnetic field is the essence of GMI response, and a much more sensitive magnetization promises a better GMI response.展开更多
Giant magneto-impedance （GMI） is effectively enhanced by the mutual magnetic interaction between two amorphous microwires. A comparative study on GMI properties of a single wire and two wires arranged in par- allel ...Giant magneto-impedance （GMI） is effectively enhanced by the mutual magnetic interaction between two amorphous microwires. A comparative study on GMI properties of a single wire and two wires arranged in par- allel mode was reported in this work. Two-peak （TP） of impedance characteristic is presented when the dc external field changed from 0 to 320 A,m-＇ in two-wire system, which is attributed to successive magnetization process in two wires induced by their magnetic interaction. And the evolution of single peak to TP phenomenon, when the distance between two wires is upto 8 ram, evidences a distance dependence of transformation from successive magnetization to simultaneous via a corresponding dis- tance dependence of magnetostatic interactions. It is pro- posed that the recombination of magnetic interaction and the shielding effect results in a distance dependency of GMI response. When the distance is 8 ram, the magneti- zation process is close to synchronous between two wires, which give rises to higher circular permeability and better GMI response. The impedance ratio AZ/Z increases from 74.5 % of single wire to 172.4 % at 10 MHz. However, when the distance is upto 12 mm, the magnetic interaction is weak and magnetization process is completely independent, and GMI response decreases, relatively. This indicates that the GMI response could be effectively improved in a two-wire connection with an optical distance, which is promising and useful for the application of high-performance GMI sensors.展开更多
基金financially supported by Taiyuan University of Science and Technology Dr. Start Research Fund (No. 20112002)
文摘The frequency dependence of magnetization process and giant magneto impedance （GMI） effect of Co-rich melt-extracted amorphous wires was studied by Kerr effect and impedance analyzer, respectively. It is demonstrated that the transverse Kerr intensity and the corresponding GMI response increase with increasing frequency, which contributes to the upgraded skin effect. However, the skin depth has a slothful trend with frequency when it is up to the megahertz range, which gives rise to the transformation of magnetization. The process is much more sensitive to the direct current magnetic field and the sensitive change of the circular permeability, and GMI response is observed as its consequence. This proves that the evolution of circumferential magnetization and the corresponding permeability with the direct current magnetic field is the essence of GMI response, and a much more sensitive magnetization promises a better GMI response.
基金financially supported by the Dr.Start Founding of Taiyuan University of Science and Technology(No.20112002)
文摘Giant magneto-impedance （GMI） is effectively enhanced by the mutual magnetic interaction between two amorphous microwires. A comparative study on GMI properties of a single wire and two wires arranged in par- allel mode was reported in this work. Two-peak （TP） of impedance characteristic is presented when the dc external field changed from 0 to 320 A,m-＇ in two-wire system, which is attributed to successive magnetization process in two wires induced by their magnetic interaction. And the evolution of single peak to TP phenomenon, when the distance between two wires is upto 8 ram, evidences a distance dependence of transformation from successive magnetization to simultaneous via a corresponding dis- tance dependence of magnetostatic interactions. It is pro- posed that the recombination of magnetic interaction and the shielding effect results in a distance dependency of GMI response. When the distance is 8 ram, the magneti- zation process is close to synchronous between two wires, which give rises to higher circular permeability and better GMI response. The impedance ratio AZ/Z increases from 74.5 % of single wire to 172.4 % at 10 MHz. However, when the distance is upto 12 mm, the magnetic interaction is weak and magnetization process is completely independent, and GMI response decreases, relatively. This indicates that the GMI response could be effectively improved in a two-wire connection with an optical distance, which is promising and useful for the application of high-performance GMI sensors.
