2006 Fiscal Year Final Research Report Summary
Magnetic orientation of iron films produced by laser-deposition
| Project/Area Number |
17550066
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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 |
Inorganic chemistry
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| Research Institution | Tokyo University of Science |
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Principal Investigator |
YAMADA Yasuhiro Tokyo University of Science, Department of Chemistry, Professor, 理学部第二部化学科, 教授 (20251407)
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| Project Period (FY) |
2005 – 2006
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| Keywords | Laser-deposition / Iron films / Mossbauer spectroscopy / Magnetic orientation / Spin anisotropy |
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| Research Abstract |
Iron films deposited on Al substrates were investigated using Mossbauer spectroscopy and scanning electron microscopy. It was found that the nuclear spin orientation of iron films produced by deposition of Fe atoms vaporized by resistive heating was perpendicular to the substrate surface, while that of films produced by laser deposition of Fe was parallel to the substrate surface. The droplets produced by laser deposition have a disk-like shape and perturb the spin orientation of the film. We have demonstrated that the spin orientation of Fe films can be controlled by employing different deposition methods.
Pyrite (FeS_2) and hematite (Fe_2O_3) were laser-deposited on Al or SiO_2/Si substrates. Mossbauer spectra of the samples provided information on composition of the laser-deposited films. The samples produced at higher temperatures have compositions with fewer amounts of S atoms to have magnetic FeS, whereas the samples produced at low temperatures have compositions close to FeS_2. In both cases, samples with defects in the lattice structure were obtained. A SiO_2/Si substrate was found to stabilize FeS_2 phase better than an Al substrate. From SEM images, it was observed that droplet particles which reflect the as-deposited composition of FeS_2 were obtained at a lower temperature. The preliminary results on laser-deposition of Fe_2O_3 show that FeO and Fe_2O_3 particles with a very high density of crystal defects were produced. It was shown that laser-deposition of compounds can produce films that have different chemical species than the laser-evaporated materials. It was also shown that yields of product compounds in films vary depending on the temperature of the substrate.
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