| Project/Area Number |
11650030
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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 |
表面界面物性
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| Research Institution | OSAKA CITY UNIVERSITY |
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Principal Investigator |
KOBAYASHI Ataru OSAKA CITY UNIVERSITY, APPLIED PHYSICS, ASSISTANT PROFESSOR, 工学部, 講師 (30271373)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 2000: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1999: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | FIELD IONIZATION / SPIN-POLARIZED ION / KINETIC ENERGY DISTRIBUTION / UNOCCUPIED STATE / HELIUM ION / SURFACE / 強磁性体 |
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| Research Abstract |
The aim of this research project is to present a novel method of producing spin-polarized helium ion, He(l^2s), by utilizing the field ionization process on ferromagnetic surfaces such as Fe, Co and Ni. To demonstrate its feasibility, we newly constructed an instrument based on an atom-probe field ion microscope (AP-FIM) and conducted the direct measurement of kinetic energy distribution spectra of produced ions where the information regarding the unoccupied state densities of sample surface is convoluted.
Almost one year has been spent for constructing the vacuum chamber. The main chamber is evacuated with both a turbo-molecular pump (60 l/s) and an ion pump (55 l/s) and the base pressure of 6×10^<-8> Torr is attained. Fieldionized helium ions from a specific site on a sample surface are selectively admitted to a velocity filter called Wienfilter via a probe-hole located at the center of microchannel plate (MCP) for FIM imaging. The energy resolution for traveling ions is set at 0.2 eV.We could therefore measure a kinetic energy distribution spectrum of field-ions with good accuracy, which solely reflects the tunneling probability of electron from a helium atom into the unoccupied states of the sample surface. With appropriate filtering and electric shielding for ion-signal lines, we have attained to the primary goal of measuring the field-ion signals of Ar produced on tungsten surface by direct pulse counting method with MCP located downstream of the Wien-filter.
For more detailed analysis of the data, a new data acquisition and display system for kinetic energy distribution measurement is desirable.
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