Fully relativistic band structure of ferromagnetic Fe and Gd

A fully relativistic layer KKR theory is proposed for calculating the electronic bulk band structure of ferromagnetic crystals. Numerical results for Fe and Gd exhibit fairly extended regions in which hybridisation between majority- and minority-spin states causes a substantial reduction of the spin expectation value. Comparison with scalar relativistic calculations shows that for the 4f bands of Gd spin-orbit coupling leads to a wide splitting and a strong hybridisation with the 5d bands. Implications of the authors' results for spin-polarised photoemission and spin-dependent bremsstrahlung are discussed.