STABILITY AND KINETICS OF STEP MOTION ON CRYSTAL-SURFACES

The kinetics of monoatomic steps in diffusion-controlled crystal growt h and evaporation processes are investigated analytically using a Gree n's function approach. Integro-differential equations of motion for th e steps are derived; a systematic linear stability analysis is carried out treating simultaneously perturbations both along and perpendicula r to the steps. Morphological fluctuations of steadily moving steps in response to ambient thermodynamic noises are also studied within a ge neral Langevin formalism. Finally, a phase field model is developed to investigate the time-dependent, collective motion of steps. An applic ation of the model to a finite step train recovers a variety of kineti c behaviors such as the bunching and spreading of steps.