Electric Conductivity of a Metallic Ferromagnet and Magnetization Process

The dependence of the conductivity and the magnetoresistance of a multi‐domain metallic ferromagnet on the magnetization when current flows along a domain wall is studied. The expression for the conductivity is obtained as function of x ‐coordinate which is normal to the domain wall plane. It is shown that the region of current localization in a compensated ferromagnet has a size in the x ‐coordinate of the order of the cyclotron radius near a single domain wall and becomes of the order of the decreasing domain width under magnetization. The magnetoresistance sharply increases in an external magnetic field near the saturation region. A comparison is made with the experimental data on the magnetoresistance of a ferromagnet with domain structure. It is shown that the appearance of nuclei of reverse‐magnetized domains leads to a resistance drop in the beginning of the magnetization process.