Hysteretic magnetisation curves in the granular Cu100-xCox system

The magnetic hysteresis properties of granular Cu100-xCox alloys (x = 5 to 20) containing nanometric Co particles, prepared under different quenching conditions and submitted to various anneals, have been measured at room tem perature. Major loops (vertex field 1 X 10(4) Oe) and minor loops (vertex f ield between 1 x 10(2) and 9 x 10(3) Oe) were measured by vibrating-sample magnetometry. The features of major loops were analysed in terms of sample composition and structural state; the dependence of remanence and coercivit y of minor loops on vertex field has been analysed in detail. A novel graph ical representation method, particularly suitable for describing the detail s of the narrow hysteresis loops observed in granular systems has been prop osed and checked. (C)1999 Acm Metallurgica Inc.