Anomalous magnetoresistance effect in sputtered TbFeCo relating to dispersed magnetic moment

The electric resistance of sputtered TbFeCo has been measured at room temperature as a function of magnetic field perpendicular to the film plane. Two kinds of anomalous magnetoresistance have been observed. One is a magnetoresistance peak in the magnetization-reversal region. The other is a reversible change proportional to the applied magnetic field, appearing in the other region. The magnetoresistance peak agrees well with a curve calculated from an experimental Hall loop. The magnetoresistance peak is found to originate from magnetic domain walls. The linear magnetoresistance change for transition-metal-dominant samples appears in a direction opposite to that for rare-earth-dominant samples. It is explained in terms of the reversible orientation change in the non-S-state Tb magnetic moment, which is dispersed because of random magnetic anisotropy. >