γ-Fe single crystal thin film growing process at room temperature and its surface chemistry
| Project/Area Number |
11450280
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Metal making engineering
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| Research Institution | Tohoku University |
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Principal Investigator |
WADAYAMA Toshimasa Tohoku University, Graduate School of Engineering, Associate Professor, 大学院・工学研究科, 助教授 (20184004)
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| Co-Investigator(Kenkyū-buntansha) |
HATTA Aritada Tohoku University, Graduate School of Engineering, Full Professor, 大学院・工学研究科, 教授 (70005502)
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| Project Period (FY) |
1999 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥5,600,000 (Direct Cost: ¥5,600,000)
Fiscal Year 2001: ¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 2000: ¥2,800,000 (Direct Cost: ¥2,800,000)
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| Keywords | γ-Fe / molecular beam epitaxy / carbon monoxide / Cu / IRRAS / RHEED / LEED / MBE / 高感度反射赤外分光法 / 高速反射電子線回折 |
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| Research Abstract |
Hetero-structures of ultra-thin films formed by molecular beam epitaxy (MBE) have been widely investigated since such man-made systems are one candidate for innovating heterogeneous catalysis and microelectronics fabrication processes. It is well known that bulk Fe has a body-centered-cubic (bcc) structure below 1183 K. In contrast, face-centered-cubic (fcc) Fe thin films can be obtained on single crystal Cu (fcc) substrates by MBE even at room temperature. In situ survey of atomic or molecular behavior of such species on fcc-Fe film is quite interesting for its surface chemistry aspects. We have investigated in this research project that adsorption and desorption behavior of carbon monoxide (CO) on the various thick fcc-Fe films on Cu(100) and Cu(111) using IR reflection absorption spectroscopy (IRRAS).
It was shown that, on the Cu(100) substrate, CO molecules initially adsorbed on bridge sites and adsorbed on on-top sites with increasing coverage. For saturated adsorption of CO, the p
… More
osition and width of the on-top C-O stretch band were found to change with deposited Fe thickness and in turn the surface structures. The on-top CO species at the fcc Fe(100) surface is sharp and located at 2038 cm^<-1> at saturated coverage. At the thickness above 10 ML the band is broadened by the phase transition from fcc to bcc. It was also found that CO adsorption on the 1-3 ML films gave an additional band at 2104 cm^<-1> which is remarkably higher than the C-O stretch band of CO adsorbed on the clean Cu(100) surface, representative of the influence of Fe. For fcc Fe films of 1-4 ML on the Cu(111) substrate, where RHEED images suggest fcc Fe(111) surface the saturated CO stretch band at 90K was centered at 2000 cm^<-1>. Between 4 and 8 ML the two absorption (2032 and 2000 cm^<-1>) bands due to adsorbed CO were observed; RHEED images in this region clearly show the mixed phase of fcc (111) and bcc (110) surfaces. Above 8 ML at which the film surface transformed to the bcc structure, the band was located only at 2032 cm^<-1>. Less
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Report
(4 results)
Research Products
(10 results)
