VALIDITY OF THE GENERALIZED CURIE-WEISS LAW IN FERROMAGNETIC SYSTEMS WITH FROZEN DISORDER

Contrary to the popular belief that the use of nonlinear scaling varia bles enhances the width of the asymptotic critical region enormously a nd hence the asymptotic value of the critical exponent gamma can be de duced from susceptibility data taken over a wide temperature range abo ve T-c (Curie point), our results unambiguously demonstrate that, thou gh the scaling in nonlinear variables (generalized Curie-Weiss law) is valid over as wide a temperature range as T-c less than or equal to T less than or equal to 1.7T(c), width of the asymptotic critical regio n as well as the values of T-c, gamma, asymptotic and non-analytic cor rection amplitudes remain unaltered when instead of the linear scaling variables nonlinear scaling variables are used. The generalized Curie -Weiss law permits an accurate determination of the atomic moment in t he paramagnetic state, q(c). The finding that the ratio q(c)/q(s) much greater than 1 and scales with T-c(-1) or T-c(-2/3) provides a strong experimental evidence for weak itinerant ferromagnetism in the invest igated amorphous alloys.