IN-SITU STUDIES OF POTASSIUM HYDROGEN PHTHALATE CRYSTAL DISSOLUTION USING SCANNING PROBE MICROSCOPY

Force microscopy has been used to image, both in situ and ex situ, cry stals of potassium hydrogen phthalate (KAP) that had been grown from a queous solution. By introducing water vapor into the growth cell in wh ich the crystals are housed, a localized etching process is seen to oc cur on the (010) face, which can then be monitored by time-lapse imagi ng. The etching process results in the development of pits having two distinct morphologies, one that may be linked to local etching at defe ct sites, and the other reflecting the random nature of the condensati on process. The distribution of secondary etch sites is seen to be inf luenced by the scanning motion of the tip and a model is proposed to e xplain this observation. (C) 1996 American Vacuum Society.