Spin-dependent Band Structure Research Articles

Internal Field and Isomer Shift of Metallic Iron and Nickel

Internal field of ferromagnetic iron is evaluated on the basis of the self-consistent and spin-dependent band structure, which was calculated by the authors. The number of the 4 s electrons, (that is, the s component of the s -, p - and d - hybridized conduction bands), and the number of unpaired 4 s electrons are determined by the band wave-functions. The wave functions of the core electrons are spin-dependent because of the polarization of the conduction electrons. They are determined by the variational method in the frame of the unrestricted Hartree-Fock scheme. The calculated value of the Fermi contact term χ of iron is -4.415, while the observed value is -3.6. The agreement between theory and experiment is reasonable. A similar calculation of the Fermi contact term of nickel gives the value -5.8, while the observed value is -6.75. The isomer shift of Fe 57 is also calculated.