Study of surface magnetic structure in Co-based amorphous microwires by means of off-diagonal magnetoimpedance effect

A method for study of a surface magnetic structure in Co-based amorphous microwires with a negative magnetostriction is proposed. The method is based on the off-diagonal magnetoimpedance effect, which can be measured by the pick-up coil wound around the studied sample. The amplitude and phase of the signal in the pick-up coil were analyzed. It was observed that the amplitude and phase did not change at the moving of the pick-up coil along the sample, which denotes the uniform single-domain state at the surface of the studied microwires.