Dendritic array growth in the systems NH_4Cl-H_2O and [CH_2CN]_2-H_2O: dendrite tip behavior and the origin of side arm evolution

摘要

Dendrite side arms evolve from perturbations behind primary dendrite tips and develop with exponentially increasing amplitudes before coalescence and ripening begin. Measurements of the spacings and amplitudes of these initial perturbations extrapolate to small finite displacements at the primary tips, compatible with small oscillatory fluctuations in the mean growth velocity. The frequency of these oscillations correspond to the initial side arm spacings and this oscillatory mode is an intrinsic characteristic of dendritic growth.