DENDRITIC GROWN KINETICS AND STRUCTURE .1. PIVALIC ACID

Pivalic acid (PVA) is an organic, fcc, "plastic crystal" which has a relatively high degree of interfacial energy anisotropy. This study of PVA shows that dendrite growth velocity multiplied by the square of the tip radius is not constant with supercooling. The crystal growth kinetics of PVA differ, in this respect, from both previously observed succinonitrile behavior and theoretical scaling laws. This material displays a linear increase in vr2 with supercooling. We consider the possible effect of interfacial energy anisotropy, byoyancy-driven convection, and molecular polarity, as it affects interfacial attachment, on the dendritic growth behavior of PVA.