Crystal Growth Mechanisms and Kinetics

The scientific contributions by David Turnbull and his co-workers toward understanding crystal growth span over 35 years from the late 1940's to the present. Turnbull's early attempt (1950) to correlate interfacial energies derived from droplet supercooling measurements with other thermochemical data still provides a significant data base for estimating such energies in a variety of materials. His work with Hillig in 1956 on quantification of the screw dislocation mechanism for interfacial molecular attachment remains as a predictive theory for defect-assisted growth of faceted, and therefore kinetically hindered, interfaces. The Hillig-Turnbull screw dislocation mechanism is now ranked among such notable kinetic models for crystal growth as the Wilson-Frenkel random attachment theory and the nucleationlimited layer spreading models of Burton, Cabrera, and Frank. Turnbull's contributions and interest in elucidating crystal growth kinetics have continued throughout his long and productive career, as evidenced by his recent work with Coriell (1982) on estimates of collision limited rapid crystal growth in highly supercooled transition metals. Progress in unraveling the kinetic contributions of interfacial attachment from those of heat and solute transport will also be reviewed to provide a current context of Professor Turnbuli's contributions to the field of rapid crystallization.