Abstract
Magnetoresistance (MR) measurements of Fe-cluster-dispersed Fe–Ag films fabricated by using the ion-cluster-beam technique display the following features. (1) The giant magnetoresistance (GMR) effect is observed in the Fe/Ag granular alloys with 12 to 45 at.% Fe, whereas it is suppressed in the Fe-rich region. (2) The MR curves display both saturation- and nonsaturation-type behavior even in a high magnetic field of 140 kOe, whereas the corresponding magnetization curves easily saturate at very low fields. The salient point here is that the GMR is optimized without any heat treatment of the specimens, and the results display some unique features of the GMR in this system.