%0 Journal Article
%A S Jin
%A L.H Chen
%A T.H Tiefel
%A M Eibschutz
%A Ramamoorthy Ramesh
%B Journal of Applied Physics
%D 1994
%G eng
%P 6915-6917
%R 10.1063/1.356779
%T Modulation-induced giant magnetoresistance in a spinodally decomposed Cu-Ni-Fe alloy
%V 75
%X Giant magnetoresistance in a spinodally decomposed, bulk 60 Cu-20 Ni-20 Fe alloy is reported. An annealed, quenched, and heat-treated sample with a compositional modulation of ≲50 Å size exhibits a ΔR/R value as high as 9% at 4.2 K. Optimization of the ferromagnetic phase particle geometry through a combination of spinodal decomposition and uniaxial deformation led to a locally multilayered, superlattice-like structure and a dramatic increase in room-temperature magnetoresistance from ∼0.6 to ∼5%. This improvement in magnetoresistance is accompanied by a decrease in coercivity from ∼620 Oe in the fully decomposed material to ∼45 Oe in the optimized structure. Interestingly, this structure no longer exhibits the commonly observed temperature-dependent behavior of ΔR/R increasing at low temperatures, but rather shows a decrease at 4.2 K.