1988 Fiscal Year Final Research Report Summary
Short Range Order in Interstitial Alloys.
| Project/Area Number |
61550472
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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 |
Physical properties of metals
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
YAMAGUCHI Sadae Institute for Materials Research, Tohoku University, 金属材料研究所, 教授 (80005892)
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| Co-Investigator(Kenkyū-buntansha) |
KAJITANI Tsuyoshi Institute for Materials Research, Tohoku University, 金属材料研究所, 助手 (80134039)
HASEGAWA Masayuki Institute for Materials Research, Tohoku University, 金属材料研究所, 助教授 (80005975)
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| Project Period (FY) |
1986 – 1988
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| Keywords | Short-Range Order / Local Atomic Arrangement / Neutron Diffraction / Diffuse Scattering / Interstitial Alloy / Interstitial Ordering |
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| Research Abstract |
1) Short-range order parameters for oxygen arrangement in single crystal of Tio_<3.32> were determined by measurements of elastic neutron diffuse scattering. The short range order term were separated from the total diffuse intensity by least squares fit of the experimental intensity with a theoretical one. The first-, third and fifth-neighbor atomic arrangement of the oxygen atom has a preference to be surrounded by vacancies rather than by oxygen atoms. While, the second- and fourth-neighbor site are occupied preferentially by oxygen atoms.
2) Short-range order parameters for deuterium arrangement in single crystal of VD_<0.81> were determined by measurements of elastic neutron diffuse scattering. The preferential configrations of vacancy-deuterium atom pair are found at first-, second-, and thirdneighbors of tetrahedral interstitial sites of the host vanadium lattice whereas the deuterium-deuterium atom pairs occur at the fourth neighbors. These features are similar to those in the ordered structure below T_c.
3) Local atomic arrangements of nitrogen atoms in Nb-N and Ta-N alloys have been studied by neutron small angle scattering. The diffuse intensity of low Q region revealed the existence of the nitorogen atom clasters.
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