Surface and bulk magnetic hysteresis loops of Co-rich glass covered microwires

The investigation of the magnetization reversal process in amorphous wires and microwires is one of the most important tasks related to the use of these wires in different devices. In particular the intensive study of magnetic properties of the nearly zero magnetostriction Co-rich wires have been performed in relation with the giant magnetoimpedance (GMI) effect. This GMI effect is of great interest in sensor application. The origin of the GMI effect is related with the penetration depth of the skin effect. Consequently, investigation on the magnetization reversal in the surface area of the wire becomes a particular importance. Therefore we used the magneto-optical Kerr effect (MOKE) for magnetization reversal study as a method, which provides a quite interesting information about the magnetic properties of the surface domain structure of the wire.