Growth Kinetics of Elementary Spiral Steps on Ice Prism Faces Grown in Vapor and Their Temperature Dependence

We grew prism faces of ice crystals heteroepitaxially on a {10 (1) over bar0} CdSe wafer. Then, we observed the lateral growth of elementary spiral steps on prism faces in vapor by advanced optical microscopy. On prism faces, we found that outcrops of screw dislocations are mostly located in the interiors of prism faces and that distance L between adjacent spiral steps is uniform, whereas these two features are not observed on basal faces. We measured the velocity Vstep of elementary spiral steps on prism faces under various supersaturation and determined the step kinetic coefficient beta. Then, we revealed that the value of fi on prism faces monotonically decreases with decreasing temperature (T) from -2.6 to -25.0 degrees C. In this T range, the value of beta on prism faces is significantly smaller than that on basal faces (determined previously). We further analyzed the relation between L and driving force for crystallization Delta mu and found that at T similar to -15 degrees C, the step ledge free energy kappa on prism faces reaches a peak (8.5 x 10(-10) J/m), implying the change in surface structures at this temperature.