On the theory of nmr for the bounded diffusion of arbitrary dimension. Application of the 3He-4He solid solutions to the phase separation kinetics

The quenching theory of the pulsed NMR spin echo signal under the conditions of a detective crystal structure when spin diffusion is limited and low-dimensional, is developed. It is proved that the distribution of spin phases diffusing in a nonhomogeneous magnetic field follows the Gauss law both at low quenching times when the case of unlimited diffusion is implemented and at high quenching times when diffusion is qreatly limited under the condition that magnetic field gradient is not very high. Echo-signal dependences on magnetic field gradient for different models of the limited diffusion of arbitrary dimensions are obtained. The results are applied to interpret the experiment on decomposition kinetics of the solid 3He-4He solution