Theoretical Study on Symmetry Breaking in Crystallization
| Project/Area Number |
17540293
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Condensed matter physics I
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| Research Institution | Nagoya University |
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Principal Investigator |
UWAHA Makio Nagoya University, Department of Physics, Professor (30183213)
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| Project Period (FY) |
2005 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥3,140,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥240,000)
Fiscal Year 2007: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2006: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2005: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | crystal growth / chiral symmetry / nucleation / enantiomer / step / elastic interaction / cluster distribution / etching / 光学異性体 / 結晶表面 / クラスター |
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| Research Abstract |
1. A recent report shows that conversion of molecular chirality is realized via crystallization in a solution with grinding, in addition to the realization of a homochiral crystalline state with a.chiral molecules. Our model explaining the homochiral state for the latter system can be generalized to the system with rasemization of a molecule in the solution From the analysis of the model, we found : the relaxation time is inversely proportional to the grinding strength, 10 the monomer concentration in the final chiral state is smaller than that in the unstable rasemic state, the concentration of the dominant chiral monomers increases temporarily if the rasemization rate is =all. We plan to study duster distribution in this system.
2. We proposed a simple one variable model to describe the change of supersaturation during crystallization. The model is bared on the analysis of numerical simulation of the Becker-Doering model with strong initial supersaturation. With the model, the change
… More
of the supersaturation may be estimated for a system with weak supersaturation, for which numerical simulation is not possible.
3. In heteroepitaxial crystal growth, misfit dislocations that break translational symmetry of the adsorbate crystal are often introduced. We construct a two-dimensional lattice model with dislocations and calculated its elastic energy to determine the optimum dislocation distance. From the energies of various surface morphologies, we proposed a diagram of growth modes, which gives unified understanding of many experiments.
4. Vicinal surfaces, such as & (11D at the lx1-7x7 transition and MOD, have two coexisting structures, and the structures at the upper and the lower side of a step are different We clarified the mechanism of step wandering and bunching by the drift of adatoms induced by direct electric current
5. STM observation of the relaxation of SrTiO3 vicinal surfaces shows asymmetry between islands and holes. Detailed comparison of the data with Monte Carlo simulations, we found that the step edge diffusion bather is the origin of the asymmetry and we could determine the magnitude of the barrier energy Less
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Report
(4 results)
Research Products
(89 results)
