| Project/Area Number |
13650714
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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 |
Physical properties of metals
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| Research Institution | Yokohama National University |
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Principal Investigator |
OHNO Kaoru Yokohama National University, Graduate School of Engineering, Professor, 大学院・工学研究院, 教授 (40185343)
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| Project Period (FY) |
2001 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥4,200,000 (Direct Cost: ¥4,200,000)
Fiscal Year 2003: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2002: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2001: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | Renormalized Potential / Molecular Dynamics Method / Monte Carlo Simulation / Lattice Gas Model / Partition Function / Order-Disorder Transition / Phase Transition / Semi-Flexible Polymer Solution / 半屈曲高分子溶液 / 半屈曲性高分子鎖溶液 |
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| Research Abstract |
Atomic diffusion and order-disorder phase transition in substitutional alloys are very long-time-scale phenomena, which are far beyond the limit of applying the molecular dynamics simulations. Such phenomena can be more effectively treated in the lattice-gas models. On a completely new intuition that the partition function of the original off-lattice system should coincide with that of the lattice-gas model, we have proposed "the potential renormalization theory", which can deduce the interaction parameters of the corresponding lattice-gas model. We have applied this theory to the silicon crystal and the Cu_xAu_<1-x> alloy. That is, we have determined the interaction parameters at various temperatures by means of the potential renormalization theory and performed the lattice Monte Carlo simulations of the lattice-gas model with the resulting interaction parameters. Thus obtained thermal expansion coefficients and melting temperature of silicon agree well with the result of the preexisting molecular dynamics simulations. Moreover, the obtained phase diagram related to the order-disorder phase transition of the Cu_xAu<1-x> alloy for various compositions x reproduces well the experimental phase diagram. This latter result has recently published in J.Crystal Growth. On the other hand, we have applied this theory to the investigation of semi-flexible polymer solution and revealed that the stiffness of polymers depends on the temperature. We reported it at the ICAM-IUMRS held in Yokohama on Oct.8-13(2003). It is now highly desirable to apply this powerful method to many other systems.
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