Magnetoresistance anomaly in DyFeCo thin films

Microstructured rare-earth-transition-metal DyFeCo films have been investig ated using magnetoresistance and extraordinary Hall-effect measurements. Th e Hall loops reveal variation of coercive fields depending on the linewidth and the composition of the films. The magnetoresistance curves, with chang es up to as high as 1.3%, show positive/negative magnetoresistance peaks ce ntered on the coercive fields depending on the linewidth of the films only. The variation of the coercivity can be attributed to the magnetic moment c anting between the Dy and FeCo subcomponents and the existence of the diver ged magnetization on the edges, and the anomalous magnetoresistance peaks o bserved are discussed with the existing theories. (C) 2001 American Institu te of Physics.