Observation of higher order facets on He-3 crystals.

Faceting has been observed on He-3 crystals investigated with a low-temperature Fabry-Perot interferometer. Nine types of facets were clearly identified during growth of a bec-He-3 single crystal at a temperature of 0.55 mK, while previously only three types of facets have been seen. Because of the weak coupling between the liquid-solid interface and the solid lattice in He-3 the facets: are apparently too small to be observed in equilibrium. The number of facets: observed in our experimental conditions is consistent with the theory of dynamic roughening