Abstract
Direct-current joule heating was exploited to fabricate giant magnetoresistance (GMR) Co10Cu90 granular alloys. The Co cluster precipitation process was investigated. At T=10 K, the largest MR change of 25.0 percent has been observed for the melt-spun Co10Cu90 ribbon annealed at I=5 A. The magnetoresistance scales approximately as the inverse Co particle size. At room temperature, the dc joule-heated samples showed relatively high GMR in comparison with furnace-annealed samples, probably a consequence of smaller Co particles formed in dc joule-heated samples.