1990 Fiscal Year Final Research Report Summary
Statistical Dynamical Diffraction of X-ray from Heat-treated Si Single Crystals
| Project/Area Number |
01580049
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
結晶学
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| Research Institution | Hokkaido University |
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Principal Investigator |
TAKAMA Toshihiko Hokkaido Univ., Fac. of Eng., Associate Professor, 工学部, 助教授 (40001309)
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| Co-Investigator(Kenkyū-buntansha) |
MARUKAWA Kenzaburo Hokkaido Univ., Fac. of Eng., Professor, 工学部, 教授 (20001191)
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| Project Period (FY) |
1989 – 1990
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| Keywords | Statistical dynamical theory / Pendellosung beats / Extinction / White X-ray / Lattice strain / Energy-dispersive diffraction / 消衰補正 |
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| Research Abstract |
Effects of randomly distributed small defects on the dynamical diffraction phenomenon are studied by measuring the X-ray Pendellosung beats with respect to the wavelength. The intensity beats of white radiation diffracted from Czochralski silicon wafers were successively measured by a solid state detector in a range from 0.1 to 0.8 A. The small defects were introduced by heating the wafers 0.5 mm thick in argon gas for 25-246 hrs at 950^ﾟC.
As the heat treatment proceeded, the following changes became predominant in the Pendellosung beats : 1. The diffracted intensity increases over the whole range of wavelength. 2. The rate of increase in intensity is high in the long wave length side. 3. The spacing of the beats increases. 4. The amplitude of beats decreases. The degree of changes was dependent on the heat treatment as well as the order of reflections.
An attempt was made to interpret the results by KaTo's statistical dynamical theory of diffraction (Acta Cryst., A36(1980)770-778). The theory has been expressed in terms of the static Debye-Waller factor E, the correlation lengths of lattice phase factor tau and of amplitude of X-ray * . The observed results can be explained well by the theory, provided * is independent of the extinction distance. For example, the data for the 220 reflection from a specimen treated for 246 hrs is explained by the theory with parameters, E, tau and * of 0.906, 0.05 mum and 0.25 mum, respectively.
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