EXPERIMENTAL AND NUMERICAL STUDY OF PATTERN-FORMATION IN FACETED CELLULAR ARRAY GROWTH

In this article, a review of our recent experimental and numerical study of pattern formation in faceted cellular array growth was presented. In situ observations in transparent faceting organic compounds have revealed the dynamical features of faceted cellular growth. Cell tip splitting and loss of cells in the array have been found to be the main mechanisms for cell spacing adjustment. The time evolution of a faceted cellular array has been followed numerically. It was found that pattern formation was history-dependent and was determined by interactions in the array. These interactions were either transient or persistent, depending on the growth condition. As a result, a finite range of stable cell spacings was found under a given growth condition; that is, there was no sharp selection. The cellular structures were irregular when persistent interactions occurred, whereas relatively regular structures could be formed once the transient interactions had stopped. The implication of these observations for pattern formation in other array growth processes, such as nonfaceted cellular, dendritic, or eutectic growth, will be discussed.