The Contribution of Magnetic Dipolar Interactions to Nuclear Spin Relaxation by Vacancy‐Type Self‐Diffusion Mechanisms in Metals

The spectral densities determining the dipolar contribution to the nuclear spin relaxation times are calculated for a combined monovacancy–divacancy mechanism of self‐diffusion in solids. The treatment is based on Wolf's encounter model for monovacancies and isotopically pure crystals. Numerical results are given for isotopically pure f.c.c. and b.c.c. crystals. The extension to more than one spin species is indicated.