1997 Fiscal Year Final Research Report Summary
GRYSTALLOGRAPHIC EVALUATION OF MESOSCOPIC PARTICLES FORMED BY FGE-TECHNIQUE
| Project/Area Number |
08650024
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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 |
Applied materials science/Crystal engineering
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| Research Institution | DAIDO INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
IWAMA Saburo DAIDO INSTITUTE OF TECHNOLOGY,DEPARTMENT OF APPLIED ELECTRONICS,PROFESSOR, 工学部, 教授 (00075904)
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| Co-Investigator(Kenkyū-buntansha) |
HAYAKAWA Kenji DAIDO INSTITUTE OF TECHNOLOGY,DEPARTMENT OF APPLIED ELECTRONICS LECTURER, 工学部, 講師 (50075909)
MIHAMA Kazuhiro DAIDO INSTITUTE OF TECHNOLOGY,DEPARTMENT OF APPLIED ELECTRONICS PROFESSOR, 工学部, 教授 (50023007)
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| Project Period (FY) |
1996 – 1997
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| Keywords | Flowing Gas Evaporation technique / Mesoscopic particles / Sb ultrafine particles / Amorphous particles / Crystallization process / Structure reluxation / critical nucleus size |
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| Research Abstract |
(1)Time-dependence of rate constant for crystallization process of amorphous Sb nano-particles
Amorphopus Sb nano-particles are formed by the FGE technique under the following conditions as 6.9m/s of Ar gas velocity and 1.7kPa of the gas pressure. The particles are collected on amorphous carbon films. Two kinds of annealing are carried out in vacuum (a) pre-annealing at 70ﾟC for 6hs followed by the annealing at 150ﾟC for various durations and (b) annealing at 150ﾟC for various durations without preannealing. Time-dependence of crystallization ratio was investigated through the dark field electron microscopic image of annealed specimens. Crystallization ratio Pc can be written by the following equation (1) from the view point of homogeneous reaction of first order,
Ln(1-Pc)=Rc・t (1)
where Rc represents the rate constant of crystallization. In the case of above (b) Rc does not keep constant and shows a gradual alowing down of crystallization in every particle size. On the other hand, Rc keeps constant for long time in case of (a). Furthermore, Rc decreases with the decrease of the particle size D.The different feature shown in two cases of (a) and (b) can be explained by a reluxation of amorphous structure.
(2)Particle size distribution and its control of nano-particles formed by FGE technique
Antimony was evaporated in the flowing He gas with the velocity of 6m/s. Particle size distribution fits satisfactorily a Gaussian. Mean particle size decreases from 9.5nm to 7.0nm with increasing of evaporation temperature from 850ﾟC to 900ﾟC.This tendency may reflect a critical nucleus size.
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Research Products
(4 results)
