The contribution of 29Si ligand superhyperfine interactions to the line width of paramagnetic centers in silicon

The results of a numerical approach for the modeling of the contribution of ligand superhyperfine interactions to the line width of the paramagnetic negative vacancy and of positively charged iron centers in silicon are reported. The dependence which is obtained for the contribution to the line width on the concentration of magnetic nuclei has a linear character for low concentrations of nuclei with non-zero spin, and transforms to a square-root dependence at high concentrations. It is shown that the behavior depends on the distribution of spin density around the paramagnetic center. The results of the numerical approach are confirmed by a theoretical analysis using computations of resonance line moments.