Relativistic Effects in the Magnetic Hyperfine Structure of the 3dN4s2 Atoms

Abstract

Relativistic self-consistent-field wavefunctions have been used to calculate relativistic mean values of r-3 for the orbital, spin-dipole and spin terms of the magnetic hyperfine Hamiltonian for the 3dN4s2 atoms. These theoretical values are compared with experimental results. The relativistic contribution to the experimentally determined spin term, which is usually referred to as the Casimir contribution, has been calculated to be of the order of 5-10% for these elements. The difference between the experimental spin term and the Casimir contribution is due to the contact interaction. Semiempirical values of the contact interaction have been derived using experimental results and the theoretical values of the Casimir contribution. Experimental values of the contact term are compared with theoretical results obtained from non-relativistic spin-polarized wavefunctions and many-body perturbation calculations. New relativistic correction factors for bound and excited s states are calculated by comparing non-relativistic and relativistic spin densities obtained with restricted self-consistent-field wavefunctions. These new correction factors are compared with earlier commonly used correction factors. They have also been used to correct the theoretical non-relativistic contact contribution for relativistic effects.