Anneal-induced transformations in the transport and magnetic properties ofCoCu granulars

The electrical and magnetic properties of granular Co5Cu95, Co10Cu90 and Co 15Cu85 ribbons treated with different annealing procedures were measured fr om helium to room temperatures. The isochronous anneals had fixed heating r ate and the transformations were followed by "in situ" resistivity measurem ents. We found that the transformation occurs at nearly the same region of temperature for the three compositions. Besides, our results for magnetores istance on Co10Cu90 could be understood in the light of the re-dissolution of Co into the Cu matrix, as suggested in previous works (Miranda et al., J . Magn. Magn. Mater. 185 (1998) 331; da Silva et al., IEEE Trans. Mag., to appear). (C) 2001 Elsevier Science B.V. All rights reserved.