1999 Fiscal Year Final Research Report Summary
The Structure of Poly-molybdate Ions and It's Relevance to the Electroplating of Molybdenum Alloy
| Project/Area Number |
09305052
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (A)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Metal making engineering
|
|---|
| Research Institution | KYOTO UNIVERSITY |
|---|
Principal Investigator |
AWAKURA Yasuhiro Kyoto University, Dept. Materials Science & Engineering, Prof., 工学研究科, 教授 (70109015)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MURASE Kuniaki Dept. Materials Science & Engineering, Kyoto University, Research Assoc., 工学研究科, 助手 (30283633)
TANAKA Isao Dept. Energy Science, Kyoto University, Assoc. Prof., エネルギー科学研究科, 助教授 (70183861)
MATSUBARA Eiichiro Inst. for Materials Research, Tohoku University, Prof., 金属材料研究所, 教授 (90173864)
HAYASHI Koichi Dept. Materials Science & Engineering, Kyoto University, Research Assoc., 工学研究科, 助手 (20283632)
|
|---|
| Project Period (FY) |
1997 – 1999
|
| Keywords | Electroplated Mo-Ni alloy / Induced codeposition / Poly-molybdate ion / Atomic structure / X-ray diffraction / Factor analysis / Small angle x-ray scattering / Molybdenum complex |
|---|
| Research Abstract |
Structures of poly-molybdate ions in acid Ni-Mo aqueous solutions have been investigated by the anomalous x-ray scattering (AXS), EXAFS, small angle x-ray scattering, and factor analysis methods. In a solution containing only molybdenum ions, molybdenum ions form a poly-molybdate ion consisting of seven edge-sharing MoO6 octahedra. In a solution containing both Mo and Ni ions, there exists another poly-molybdate ion consisting of 6 edge-sharing MoO6 surrounding a Ni ion. The coordination number of Mo-Mo pairs decreases by half by adding citric ions. This indicates that the large ply-molybdate ion is decomposed to smaller molybdate ions due to formation of citric complexes. This is also confirmed by the SAXS measurements. Since molybdenum-nickel alloys are not electrodeposited from the solutions without citric ions, we expect that the decomposition of large poly-molybdate ions in the solution is closely related with the mechanism of the induced codeposition of molybdenum and nickel alloy.
|
