K. Sumiyama et al., MAGNETORESISTANCE IN FE AG GRANULAR ALLOYS PRODUCED BY ION-CLUSTER-BEAM AND SPUTTERING/, Science Reports of the Research Institutes, Tohoku University, Series A: Physics, Chemistry, and Metallurgy, 39(1), 1993, pp. 69-72
Magnetoresistance(MR) effect has been observed for Fe/Ag granular allo
ys. In the Fe-Ag alloys made by sputtering, MR is rather small at the
as-deposited state. The MR effect is enhanced as Fe atoms form cluster
s by annealing the supersaturated fcc solid solution: it becomes large
st after annealing at 570 K and decreases after annealing at higher te
mperatures. In the Fe/Ag granular alloys made by ion-cluster- beam (IC
B) method, MR is largest at the as-deposited state and it monotonicall
y decreases with annealing at higher temperatures. MR of the as-deposi
ted state does not saturates even at a high field of 140 kOe. This fea
ture is more marked in the sputter-deposited alloys than in the ICB-de
posited ones. These results indicate that the MR effect is optimized i
n the ICB-deposited alloys, because nanoscale ferromagnetic Fe cluster
s have been for-med in the as-deposited state in contrast to their for
mation by annealing in the sputter-deposited alloys.