SPIN-LATTICE RELAXATION-TIME IN THE PHASE-SEPARATED HCP HE-3-HE-4 MIXTURES

Spin-lattice relaxation time in a mixture of a 3.18% He-3 initial conc entration is measured by a pulsed NMR technique at a frequency of 250 kHz, during phase separation. The relaxation time in a concentrated BC C phase is found to differ substantially from that in the initial mixt ure and does not depend on temperature in the whole range of its exist ence. It is shown that relaxation is governed by the Zeeman-exchange m echanism. In a dilute HCP daughter phase relaxation time increases on cooling, what is treated as a manifestation of the inverse He-3 consen tration dependence.