CONDUCTIVE AND RADIATIVE HEAT-TRANSFER, DIFFUSION AND INTERFACE KINETICS IN SPHERICALLY SYMMETRICAL VAPOR GROWTH - APPLICATION TO HGI2

A spherically symmetric model for crystal growth from vapour is presented which includes conductive and radiative heat transport, mass diffusion and interface kinetics. Criteria are derived for the regimes in which growth is limited by either interface kinetics, mass or heat transport. Radiation heating of the growing crystal by an external heater is shown to be a possible reason for growth cessation at an undercooling-dependent, critical crystal size. The rounding of polygonal crystal shapes is interpreted as the truncation of the crystal apexes and edges by the equilibrium isotherm.