Influence Of Driving Field On LDGMI Effect Of Fe-based Nanocrystalline Ribbons

In recent years,the giant magneto-immpedance?GMI?effect of soft magnetic materials has some advantages of high sensitivity,small volume and low power losses,which has became one of the main methods for the development of weak magnetic sensors,and caused widespread intentions at home and abroad.Currently,the dependence of driving field on the GMI effect has been researched by the traditional measurement mode of four probes.But the problems of sample welding and Joule heating effect have limited the intensity of driving field.In this paper,we investigated the GMI effect of Fe_73.5Cu₁Nb₃Si_13.5B₉ nanocrystalline ribbon under longitudinal driven model.We have analyzed the characteristic of hysteresis loops with different pieces of nanocrystalline ribbons,and the influences of the external magnetic field and pieces of ribbons on the sample LDGMI effect,the corresponding induction voltage wave and the distribution characteristics of harmonics.The main conclusions are as follows:?1?When the pieces of Fe_73.5Cu₁Nb₃Si_13.5B₉ nanocrystalline ribbon increased,we have found that the magnetic dipolar-dipolar interaction existed between neighboring nanocrystalline ribbons.The anisotropy field and saturation magnetization also linearly increased,but coercive force kept almost zero,the magnetic structure further inclined to the transverse structure.?2?The LDGMI curves of all samples had showed "small platforms" in low ac driving field.The "platform" width was modulated by the intensity and frequency of driven field.Simultaneously,magnetic dipole-dipole interaction existed in neighboring nanocrystallin ribbon,the platform width and the anisotropy field of samples linearly increased with the pieces of nanocrystalline ribbon added.?3?The different samples have totally generated nonlinear magnetization under the condition of high driving field,their LDGMI curves also have exhibited "big platforms".When the driving field enhanced,the smaller the sample anisotropy field is,the higher the degree of nonlinear magnetization is,the platform width of the LDGMI curves also gradually broadened;Simultaneously,the frequency spectrum of different samples have exhibited different forms.The sample characteristic frequency with small anisotropy field is easier to move to high frequency range than that of other sample,the reason is that these sample have different degree of the nonlinear magnetization with the same condition.