NMR Study of Disordered Inclusions in the Quenched Solid Helium
Abstract
Phase structure of rapidly quenched solid helium samples is studied by the NMR technique. The pulse NMR method is used for measurements of spin-lattice T1 and spin-spin T2 relaxation times and spin diffusion coefficient D for all coexisting phases. It was found that quenched samples are two-phase systems consisting of the hcp matrix and some inclusions which are characterized by D and T2 values close to those in liquid phase. Such liquid-like inclusions undergo a spontaneous transition to a new state with anomalously short T2 times. It is found that inclusions observed in both the states disappear on careful annealing near the melting curve. It is assumed that the liquid-like inclusions transform into a new state - a glass or a crystal with a large number of dislocations. These disordered inclusions may be responsible for the anomalous phenomena observed in supersolid region.