DETERMINATION OF ANISOTROPY OF CRYSTAL-MELT INTERFACIAL ENERGY FROM THE OBSERVED GRAIN BOUNDARY GROOVE SHAPES AT MULTIPLE ORIENTATIONS

A specialized high-precision thermal gradient furnace with a rotating stage was developed for in situ observation of the equilibrated grain boundary groove shapes at multiple crystallographic orientations in transparent materials. Anisotropies of solid-liquid interfacial free energy for the distillated succinonitrile (SCN) and pivalic acid (PVA) are determined experimentally through direct observation of the equilibrated grain boundary grooves at the multiple crystallographic orientations stabilized within a controlled thermal gradient. The average anisotropies of solid liquid interfacial energy for distillated SCN and PVA are found to be 0.42 and 3.12% from observed grain boundary groove shapes at multiple crystallographic orientations. Details related to the experimental apparatus and experimental procedures are given.