Study on the occurrence of spontaneously established perpendicular exchange bias in Co{sub 49}Pt{sub 51}/IrMn bilayers

Journal Article · Wed May 07 04:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4868915· OSTI ID:22273734

Tsai, C. Y.; Lin, K. F. ^[1]; Hsu, Jen-Hwa ^[2]; Saravanan, P. ^[2]

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1. Graduate Institute of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan (China)
2. Department of Physics, National Taiwan University, Taipei 106, Taiwan (China)

In this study, perpendicular exchange bias (PEB) effect in the as-grown Co{sub 49}Pt{sub 51}/IrMn bilayers was demonstrated at room temperature using single-layered Co{sub 49}Pt{sub 51} alloy thin film as ferromagnetic (FM) layer. Several unusual features were observed in this system, viz.,: (i) the PEB was spontaneously established without any external magnetic field treatments, (ii) single-shifted loops were obtained rather than double-shifted ones, and (iii) the spontaneous PEB effect was accompanied by a reduction in perpendicular coercivity, H{sub c⊥} from 1024 to 632 Oe. The results of x–ray diffraction revealed the formation of IrMn (111) texture. Training effect studies indicate that the PEB effect is stable in this system with less than 5% variation in PEB value within 15 repetitive scans. Significant reduction in the PEB effect was found for the CoPt/IrMn films either grown or subjected to post-annealing under external magnetic field (H{sub ind}). The thickness dependence of PEB effect with respect to the FM and antiferromagnetic layers were also investigated and a largest PEB value of 533 Oe was obtained for the sample grown with 3-nm thick CoPt and 10-nm thick IrMn layers. The results of present study thus establish an opportunity to realize PEB effect in the absence of external field during fabrication.

• OSTI ID: 22273734
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 17 Vol. 115; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANNEALING
ANTIFERROMAGNETISM
COBALT ALLOYS
COERCIVE FORCE
CRYSTAL STRUCTURE
FERROMAGNETIC MATERIALS
INTERFACES
IRIDIUM ALLOYS
LAYERS
MAGNETIC FIELDS
MANGANESE ALLOYS
PLATINUM ALLOYS
TEMPERATURE RANGE 0273-0400 K
THIN FILMS
X-RAY DIFFRACTION