Exchange-coupled spin-fluctuation theory: Application to Fe, Co and Ni

Finite-temperature properties are modeled for the itinerant-electron ferromagnets Fe, Co and Ni by employing a spin-fluctuation theory where the modes are coupled by inter-atomic exchange interactions. Our method is based on the density functional theory using the LDA. The latter yields all parameters derived from constrained ground-state properties of noncollinear spin configurations to calculate ab initio the Curie temperatures and the magnetic susceptibilities. Our results are in fair agreement with experimental data.