In situ observation of growth process of alpha-L-glutamic acid with atomicforce microscopy

The growth kinetics of the (111) and (001) faces of an alpha-L-glutamic aci d crystal was investigated from the measurements of the growth rates, coupl ing with in situ surface observation using atomic force microscopy (AFM), T he data of the growth rates were examined by applying the theoretical equat ions of the BCF and NaN models. The results indicate that the growth mechan ism is not due to the screw dislocation but to the two-dimensional nucleati on, i.e,, the NaN model, It was confirmed by AFM observation that both the (111)and (001) faces grew with the "nucleus above nucleus" (NaN) mechanism. However, the difference of the two-dimensional nucleation behavior was obs erved between the faces. The growing surface of the (111) face was also obs erved in the presence of L-phenylaline (L-Phe) and the pinning effect by L- Phe on the growing step on the (111) face was confirmed. This result suppor ts the mechanism of the additive effect, which was proposed previously. : ( C) 2000 Academic Press.