Influence of the sample length and profile of the magnetoimpedance effect in FeCrSiBCuNb ultrasoft magnetic wires.

The magnetoimpedance (MI) effect has been investigateded in Fe[sub 63.5]Cr[sub 10]Si[sub 13.5]B[sub 9]Cu[sub 1]Nb[sub 3] alloy wire exhibiting an ultrasoft magnetic character after suitable thermal treatment at 525 °C. It has been measured as a function of the sample length and of the distance to the ends of the wire (MI profile). The observed dependence on both parameters is correlated with the local particularities of the magnetization process: complex domain structures emerging near the ends to decrease the magnetostatic energy modify the local magnetic susceptibility and consequently the MI response. The present study points out the importance of geometrical dimensions of samples and measuring conditions when reporting numerical values in MI studies. This wire, showing large magnetoimpedance together with optimized soft magnetic behavior and improved corrosion properties seems to be indicated as a sensing element in GMI based sensors. [ABSTRACT FROM AUTHOR]