Limits on surface vicinality and growth rate due to hollow dislocation cores on KDP {101}

Atomic-force microscopy measurements on KDP {101} faces are presented which show that the terrace width W on vicinal dislocation growth hillocks is nearly independent of supersaturation sigma and Burgers vector b, in contradiction to simple Burton-Cabrera-Frank models. An analytical model taking into account the effect of dislocation cores on step rotation is presented which predicts a dependence of W on sigma and b, in good agreement with the measurements. Using these results, we rescale macroscopic growth rate data onto a single Arrhenius curve, which gives a value of 0.33 eV for the activation energy of step motion.