Spin-lattice relaxation in phase-separated He-3-He-4 solid solution

The spin-lattice relaxation time in a He-3-He-4 solid solution with the initial concentration 3.18%He-3 is measured during phase separation by using the pulsed NMR technique. The relaxation time in a concentrated bbc phase formed as a result of phase separation is found to be independent of temperature over the entire range of its existence and is determined by the Zeeman-exchange interaction mechanism. In the dilute hcp daughter phase, the spin-lattice relaxation time increases on cooling according to the law T-1 similar to x(-n), where n=0.88+/-0.12, and x is the He-3 concentration. The values of T-1 in this phase coincide with the values corresponding to a homogeneous (nonseparated) solution of the same concentration. (C) 1997 American Institute of Physics.