2004 Fiscal Year Final Research Report Summary
Structure and magnetism of ferromagnetic nanodot arrays made using nanopatterns on N-adsorbed Cu surfaces
| Project/Area Number |
15510088
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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 |
Nanostructural science
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| Research Institution | The University of Tokyo |
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Principal Investigator |
KOMORI Fumio the University of Tokyo, Institute for Solid State Physics, Associate Professor, 物性研究所, 助教授 (60170388)
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| Co-Investigator(Kenkyū-buntansha) |
NAKATSUJI Kan the University of Tokyo, Institute for Solid State Physics, Research Associate, 物性研究所, 助手 (80311629)
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| Project Period (FY) |
2003 – 2004
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| Keywords | magnetic nanodot / one dimensional array of ferromagnetic dots / STM / surface electronic states / magnetic anisotropy / photoemission spectroscopy / lattice strain |
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| Research Abstract |
When the surfaces is covered by 0.3 ML of N on the flat surface, square patches of Cu(001)-c(2x2)N with the size of 5x5 nm^2 are arranged regularly as a square lattice pattern. By depositing magnetic transition metals on this surface, we can prepare a magnetic dot array of a square arrangement. We studied the mechanisms of the nanopattern and nanodot formations, and their magnetic properties.
On a vicinal (001) surface to <100> with 0.3 ML nitrogen, we can form one-dimensional array of square N-adsorbed patches separated by monatomic steps. On this surface, one-dimensional array of Co dots are made by depositing 1-2 ML Co. We measured the magnetization curves using magneto-optical Kerr rotation method in ultra high vaccum. Uni-axial magnetic anisotropy parallel to the step edge was found on this sample while the anisotropy is fourfold in the Co films on a flat Cu(001) surface.
We measured soft X-ray absorption spectra and magnetic circular dichronism on the Co nanodot array. The observed nitrogen K-edge adsorption spectra indicate that the nitrogen is bonding to Co atoms. The dichroism of Co L2,3 was observed as a function of averaged thickness of Co. With decreasing it, the orbital magnetic moment increases.
The change of the surface electronic structures due to the lattice strain was observed using photoemission spectroscopy on the partially nitrogen adsorbed Cu(001) surfaces. The results are consistent with the first-principles calculations. The segregation of nitrogen on Co dots in this system was found using XPS and STM, and is attributed to the lattice strain due to the island formation.
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Research Products
(12 results)
