Experimental study of surface domain structure effects on off-diagonal magnetoimpedance in glass-coated Co-based microwires

The off-diagonal magnetoimpedance in glass-coated Co-based amorphous microwires is studied using a pick-up coil wound around the sample. The first and second harmonics in the pick-up coil voltage were measured as a function of the external magnetic field. It was observed that the first harmonic in the voltage corresponding to the linear off-diagonal magnetoimpedance was very small. This fact is attributed to the existence of the regular bamboo domain structure within a surface layer of the microwire. On the contrary, the second harmonic in the voltage differed from zero, which is related to the domain-walls motion