Damping of crystallization waves at the solid-liquid interface of helium

The low-temperature behavior of ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ crystallization waves has been studied from 0.03 to 0.5 K. From the damping of these waves we have determined the interfacial growth resistance, (Km${)}^{\mathrm{-}1}$. At the lowest temperatures, (Km${)}^{\mathrm{-}1}$ is consistent with the assumption that the growth velocity is limted by the scattering of ballistic phonons by the moving interface. Above T≊0.25 K, (Km${)}^{\mathrm{-}1}$ increases more slowly with temperature, indicating a decrease in the phonon contribution from that observed at lower temperatures.