The influence of magnetic field on melting and growth  of solid 3He

Dr.  Reyer Jochemsen,
Kamerlingh Onnes Laboratorium, LION, Leiden University,. Leiden, The Netherlands
Recent experiments on crystal growth and crystal shape in 3He at zero magnetic field by Tsepelin et al in Helsinki have revealed many new facets and strong anisotropy in the growth rates. One of the remarkable conclusions is the apparently dominating influence of the elastic interaction between the steps on the facets. Also unexpected was the apparent stiffness of the 3He solid/liquid interface as compared to the situation in 4He, while the bulk 3He solid is know to be softer than 4He. It has been suggested that this is related to the magnetic interaction and ordering in the solid 3He. Since 3He presents the unique possibility of investigating the influence of a magnetic field (the nuclear magnetic energy μB can be made largerthan the thermal energy kT) on the crystal growth properties, we have experimentally studied the shape and growth rate of solid 3He in magnetic field at temperatures down to 0.3 mK.  Our optical access cryostat with low temperature CCD has allowed clear images of the crystals. The latest experimental images/movies and data will be presented.