1987 Fiscal Year Final Research Report Summary
Studies on the size of growth unit in crystal by means of light scattering method
| Project/Area Number |
61460236
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
結晶学
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
SUNAGAWA Ichiro Fac.Science.Tohoku University.Professor, 理学部, 教授 (20004426)
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| Co-Investigator(Kenkyū-buntansha) |
TSUKAMOTO Katsuo Fac.Sci.,Tohoku University,Assistant, 理学部, 助手 (60125614)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Crystal growth / Growth unit / Aqueous solution / Cluster / Laser particle size analyser / Dynamic light scattering method / 光混合法 / 光子相関法 |
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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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