| Budget Amount *help |
¥8,200,000 (Direct Cost: ¥8,200,000)
Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1986: ¥7,700,000 (Direct Cost: ¥7,700,000)
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| Research Abstract |
It is an essential aspect in understanding the mechanism of crystal growth,perfection and morphology of crystals to clarify whether crystals grow by the incorporation of atomic or ionic entities or larger growth units,like clusters. All the existing theories of crystal growth mechanisms are based on an assumption that the growth units are atomic or ionic entities,whereas there are ample experimental evidences suggesting the presence of larger growth units in vapour or solution from which crystals grow.
It was the aim of this project toinvestigate this problem by means of laser beam dynamic light scattering method. For this purpose,a new experimental set up.was constructed,which consists of newly designed part of observation and measurement(composed of laser light source, thermostated growth cell,optical microscope with two pin holes,photomultiplier)and a data processing part (Otsuka Electronics,LPA-3000).Cluster sizes were measured,by utilizing Doppler effect due to Brownian movement,bymeans of optical homodyne method (dynamic light scattering method).After the reliability of the experimental set up was checked using standard samples, the method was-applied to saccharose and ADP aqueous solutions whose concentrations were changed gradually from undersaturation,saturation to supersaturation. Itwas found that even the clusters of a few n.m. size could be detected and that the cluster sizes of both solutions increased as increasing the concentration.This method can be applied to the measurement of cluster sizes in real system,in which crystals are growing.
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