1.55-MHz pulsed NMR measurements have been made on solid krypton samples containing natural abundance (11.55%) ${}_{}{}^{83}{}_{}{}^{}\mathrm{Kr}$ and isotopically enriched (73.1%) ${}_{}{}^{83}{}_{}{}^{}\mathrm{Kr}$ between 37.2 and 115.6 K. The computer-controlled experiments determined spin-lattice relaxation rates ${\Gamma }_1$ and ${\Gamma }_{1\rho }$ as well as the central and noncentral transverse rates ${\Gamma }_{2c}$ and ${\Gamma }_{2q}$. ${\Gamma }_1$ principally reflects quadrupolar Raman relaxation of the spin-(9/2) ${}_{}{}^{83}{}_{}{}^{}\mathrm{Kr}$ by thermal phonons. There also are resolvable contributions from ${\mathrm{N}}_2$ impurities and from thermal vacancies. ${\Gamma }_{1\rho }$ components arise from independent fluctuating quadrupole interactions and ${\Gamma }_{2c}$ in the warm solid is dominated by quadrupolar intraspin cross relaxation. The temperature variations of ${\Gamma }_{2c}$ and ${\Gamma }_{1\rho }$ provided a determination of the coefficient of atomic self-diffusion in solid krypton: D=(8.$7_{\mathrm{-}2.2}^{+3.0\mathrm{}}$)exp[-( 5190±50 cal/mole)/RT] ${\mathrm{cm}}^2$/sec. A vacancy contribution to ${\Gamma }_{2q}$ near 100 K yields the difference between the mobility and formation energies ($E_M$-$E_F$)=1300±100 cal/mole and thus the individual values $E_M$=3245±75 and $E_F$=1945±75 cal/mole.

• Received 17 December 1985

DOI:https://doi.org/10.1103/PhysRevB.33.5999