EXCHANGE-COUPLED SPIN-FLUCTUATION THEORY - APPLICATION TO FE, CO, ANDNI

Finite-temperature properties are modeled for the itinerant-electron f erromagnets Fe, Co, and Ni by employing a spin-fluctuation theory wher e the modes are coupled by interatomic exchange interactions. Our meth od is based on the density functional theory using the local density a pproximation. The latter yields all parameters derived from constraine d ground-state properties of noncollinear spin configurations to calcu late nb initio the Curie temperatures, the magnetic susceptibilities, and, furthermore, the hcp-fcc phase transition of Co. Our results are in fair agreement with experimental data.