Hyperfine field and isomer shift in ferromagnetic Fe-Cr alloys

The valence contact spin and charge densities at Fe sites in ferromagnetic Fe-Cr alloys are calculated using the discrete variational method. The hyperfine field at Fe nucleus is expressed as a linear sum of a core term, that is proportional to the local 3 d moment, and a valence term, which is proportional to the valence spin density. The dependence of the hyperfine field, the contact charge density and the 4s magnetic moment on the number and orientation of chromium atoms in the first and second shells is studied. Comparison to experimental data is made.