Magnetoresistance in a deformed Cu-Ni-Fe alloy with ultrafine multilayer structure

Abstract:

The creation of a giant magnetoresistance (GMR) effect in a spinodally decomposed and deformed Cu-20% Ni-20% Fe alloy is reported. The alloy is processed to contain a locally multilayered superlattice-like structure with alternating ferromagnetic and nonmagnetic layers with a size scale of 10–20 A. The microstructural modification produced a dramatic improvement in room-temperature magnetoresistance ratio from —0.6 to —5%. The observed magnetoresistance is most likely related to the spin-dependent scattering at the two-phase interface and in the ferromagnetic phase, although the exact mechanism involved may be qualitatively different from the usual GMR picture. A rather unusual temperature-dependence of magnetoresistance ratio, i.e., the room-temperature value being greater than that at 4.2 K, was found. © 1994, Materials Research Society. All rights reserved.