Appearance of anomalous phase in $^4$He crystal in the presence of small $^3$He impurity

The kinetics of formation of an anomalous phase from a solution with a small $^3$He impurity was studied in the temperature range 0.2-0.7 K up to a supersaturation of $\sim 30$ mbar. The phase diagram was determined for normal and anomalous growths. It is found that, in the presence of impurities, the formation of a fast-growing state is retarded. This experimental fact indicates that the dissipative processes in fluids have an appreciable effect on the phase formation kinetics. The retardation is, possibly, caused by the direct interaction of an impurity with the crystal surface.