Electrical resistivity and magnetoresistance in Fe-B-C amorphous alloys

Abstract

The low-temperature electrical resistivity in Fe80B20-x (x=0, 2 and 8) shows a well defined resistivity minimum at Tmin. Both Tmin and the depth of the minimum increase with x whereas a magnetic field as high as 39 kOe hardly changes either feature. This indicates that the origin of the resistivity minimum may be other than magnetic. The data below Tmin fit better with rho varies as ln T than rho varies as square root T. The magnetoresistance data seem to suggest the presence of both localisation and correlation effects. The high-field negative magnetoresistance in Fe80B20C0 varying as square root H is in quantitative agreement with the localisation picture.