Solid-Liquid Interface Motion of ⁴He in an Acoustic Field

Abstract

When acoustic waves were applied to the solid-liquid interface of ⁴He perpendicularly, from the solid side, the solid was megted at high temperatures and grown at low temperatures. This means that the direction of the force on the interface was inverted at an inversion temperature, T _i. We attributed this effect to the acoustic radiation pressure, which induced crystallization and megting [Phys. Rev. Lett. 90, 075301, (2003)]. Temperature dependence of the interface motion by acoustic waves was investigated in several surface orientations. Anisotropy of T _i was found and T _i was lower on a vicinal surface than on a rough surface.