The evolution of magnetic order in CrFe alloys. III. Ferromagnetism close to the critical concentration

For pt.II see ibid., vol.13, p.451 (1983). The results of a series of neutron small-angle scattering measurements on ferromagnetic CrFe alloys close to the critical concentration for ferromagnetism (c F ) have been analysed to yield the concentration and temperature dependence of the magnetic inverse correlation range, kappa 1 (c,T). It is found that kappa 1 does not go to zero at T c , but varies as (c-c F )((T-T C )/T C ) nu + kappa R where nu =1.2+or-0.1. At low temperatures the alloys showed significant long-range inhomogeneity in the ferromagnetic correlations; this became more pronounced as the concentration approached c F . These features are discussed in relation to the other complex magnetic properties of these highly disordered ferromagnets.