Magnetic small-angle scattering from molten elements iron, cobalt, and nickel

Scattering of neutrons (lambda = 0.7 A) from molten iron was carried out at 16000C (Tsub(melt) = 15360C; Tsub(Curie) = 7700C) within the region of q = 0.2-2.0 A-1. A pronounced small-angle scattering effect was observed for q<= 1.2 A-1, which is explained by magnetic scattering from spin fluctuations. A correlation length xi = 2.7 A was obtained. The plot of log xi versus log [(T-Tsub(Curie))/Tsub(Curie)] together with the xi values obtained from solid iron shows that all measured xi values can be described by the law xi = 2.15[(T-Tsub(Curie))/Tsub(Curie)]sup(-0.5). Molten cobalt at 15500C (Tsub(melt) = 14930C; Tsub(Curie) = 11270C) yields a correlation length of 6.3 A. Finally the results from a corresponding experiment on molten nickel at 15000C (Tsub(melt) = 14540C; Tsub(Curie) = 3580C) are presented. However, the observed scattering effect is very small compared with that from the two other elements. (Auth.)