Magnetic properties in granular Co10Cu90 alloys: the effect of random anisotropy and interparticle interactions

The magnetization curves of Co10Cu90 as-east and annealed melt-spun ribbons were measured for 4.2 < T < 600 K. The narrow hysteresis found in these sy stems present an unusual temperature dependence of the coercive field H-c(T ), in most samples with a decrease in the low T region due to superparamagn etic unblocking followed by an increase in T and a maximum around room temp erature. These results are explained in analogy to soft nanocrystalline all oys using the random anisotropy model and the existence of interparticle in teractions. (C) 2001 Elsevier Science B.V. All rights reserved.