GIANT MAGNETORESISTANCE OF FE-CLUSTER-DISPERSED AG FILMS

We report on giant magnetoresistance (GMR) of Fe-cluster-dispersed Ag films. Composite thin films with a thickness of about 2000 angstrom an d the compositional ratios Fe/Ag = 20/80, 33/67 and 45/55 have been pr oduced by an ionized cluster beam (ICB) technique. Measurements of X-r av diffraction, transmission electron microscope, magnetization and ma gnetoresistance display the following salient features: (1) GMR is obs erved without any heat treatment of the samples, (2) GMR of about 25% is obtained for Fe/Ag = 33/67, and (3) MR is not saturated even in a m agnetic field of 140 kOe for these specimens, although the magnetizati ons are saturated in a magnetic field of about 3 kOe.