TEMPERATURE-DEPENDENT ELECTRONIC-STRUCTURE AND FERROMAGNETISM OF BCC IRON

The influence of electron correlations on the temperature dependence o f the electronic structure of ferromagnetic bcc iron is investigated b y the use of a many-body evaluation of a generalized model of magnetis m. The one-particle part of the model Hamiltonian is taken from a LDA band-structure calculation. The model contains only two parameters, an intraband Coulomb interaction U, and an interband exchange J. With 1. 8 eV and J=0.2 ev the self-consistent model solution yields a T=0 mome nt of about 2.04 mu(B) and an exact curie temperature of 1044 K. Detai ls of the magnetic behavior of Fe can be traced back to a striking tem perature variation of the quasiparticle density of states. Typical dif ferneces in the magnetic behavior of Fe can be traced back to a striki ng temperature variation of the quasiparticle density of states. Typic al differences in the magnetic behavior of Fe and Ni are worked out.