| Project/Area Number |
11650333
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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 |
Electronic materials/Electric materials
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| Research Institution | Nihon University |
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Principal Investigator |
ITOH Akiyoshi Nihon-University, Collage of Science & Technology, Professor, 理工学部, 教授 (60059962)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAGAWA Katsuji Nihon-University, Collage of Science & Technology, Associate Professor, 理工学部, 助教授 (20221442)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2000: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1999: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | molecular dynamics method / simulation / superlattice / giant magnet resistance / GMR / CPP-GMR / microfabrication / FIB |
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| Research Abstract |
The recording density of HDDs rises at an annual rate of 80 to 100 %. The giant magnetoresistance (GMR) effect in Co/Cu multilayers is one of the important issues for achieving high sensitive magnetic head. It is known that current-perpendicular-to-the-plane (CPP) GMR shows higher MR ratios than current-in-plane (CIP) GMR. It is commonly known that GMR effect depends on the nanostructure at the interface in the superlattice.
(1) For the purpose of clarifying the nanostructure at the surface during the film formation process, we performed molecular dynamics (MD) simulations for the Cu deposition behavior on aCu (111) single crystal substrate. After the deposition of 0.6 Cu atoms monolayer on a single crystal substrate, [ABC] and [AB/A] structures were observed at the surface. With increasing thickness of the deposited layer, [ABC] and [AB/A] structures contacted each other, and stacking faults appeared inside the third deposited layer. Then the grain structure appeared inside the fourth deposited layer merely over the area where the stacking faults were observed inside the third deposited layer. Then, the dependence of the interface structure to the kinetic energies of incident atoms derived from simulations corresponds well to the experimental results of NMR spectram.
(2) We performed micro fabrication of Co/Cu multilayers using a focused ion beam (FIB) etching machine to increase MR ratios by changing the current flow path. Ga contamination of the specimen caused by FIB processing was within 3 nm. As a result, the MR ratio increased from 4.55 % to 8.90%.
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