The theory of nuclear spin diffusion due to paramagnetic impurities in a diamagnetic crystal

The diffusion of nuclear magnetization inside a diffusion barrier, due to modulation of the fluctuation spin operator of a magnetic ion by the interaction between nuclei, is treated to third order of perturbation theory. Cross-relaxation transitions of two types are being modulated. These are the transitions in which a pair of nuclei is mutually reoriented either due to a dipole-dipole interaction between them or by the coupling of each nucleus to the electron spin. The relative effectiveness of these processes depends on the experimental conditions.Translated from Izvestiya Vysskikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 76–80, November, 1975.The author is grateful to B. I. Kochelaev for discussing the results of this work.