2007/07/31 by S. Sasaki, Satoshi Sasaki, Frédéric Caupin +2 · 2 citations
Earth and Planetary Sciences · Physics and Astronomy · #Atomic and Subatomic Physics Research #High-pressure geophysics and materials #Quantum, superfluid, helium dynamics #cond-mat.other #cond-mat.stat-mech
paper · pdf · doi:10.1103/physrevlett.99.205302
4 pages, 4 figures
arxiv created 2007/09/12 · openalex publication_date 2007/11/15 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We have observed boundaries between hcp 4He crystal grains in equilibrium with liquid 4He. We have found that, when emerging at the liquid-solid interface, a grain boundary makes a groove whose dihedral angle 2theta is nonzero. This measurement shows that grain boundaries are not completely wet by the liquid phase, in agreement with recent Monte Carlo simulations. Depending on the value of theta, the contact line of a grain boundary with a solid wall may be wet by the liquid. In this case, the line is a thin channel with a curved triangular cross section, whose measured width agrees with predictions from a simple model. We discuss these measurements in the context of grain boundary premelting and for a future understanding of the possible supersolidity of solid 4He.