Abstract
We have fabricated spin valves which had the simple structure of Si/SiO2/CoFe2O4 (40 nm)/Co (2 nm)/Cu (2 nm)/Co (4 nm) by rf-magnetron sputtering at room temperature. A hard magnetic and insulating Co-ferrite film was used as a pinning layer. As-deposited films showed a high sheet resistance of 36.3 Ω/square and a magnetoresistance (MR) ratio of 4.5%. The MR property of the spin valves was significantly improved by postannealing in a vacuum. An MR ratio of 10.5% was attained by annealing at 300°C for 4 h. The variation in sheet resistance was approximately 3.9 Ω/square. This remarkable increase in MR ratio could be attributed to the construction of clear Co/Cu/Co/CoFe2O4 interfaces and the improvement of the magnetic property of the Co-ferrite layer by postannealing.
Original language | English |
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Pages (from-to) | 6865-6868 |
Number of pages | 4 |
Journal | Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers |
Volume | 42 |
Issue number | 11 |
DOIs | |
Publication status | Published - 2003 Nov |
Externally published | Yes |
Keywords
- Annealing
- CoFeO
- Hard magnetics
- Magneto-resistance
- Spin valve
ASJC Scopus subject areas
- Engineering(all)
- Physics and Astronomy(all)