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Dot arrays of L1{sub 1} type Co-Pt ordered alloy perpendicular films

Journal Article · · Journal of Applied Physics
DOI:https://doi.org/10.1063/1.3068539· OSTI ID:21190153
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  1. Research Institute of Electrical Communication, Tohoku University, Sendai 980-8577 (Japan)
  2. Institute of Multidisciplinary Research for Advanced Material, Tohoku University, Sendai 980-8577 (Japan)

Magnetic properties of dot arrays of L1{sub 1} type Co-Pt ordered alloy perpendicular films were studied. L1{sub 1}-Co-Pt films with a large uniaxial magnetic anisotropy K{sub u} of the order of 10{sup 7} erg/cm{sup 3} were fabricated at a substrate temperature of 360 deg. C using ultrahigh vacuum sputter film deposition. Dot patterns with dot diameters of 70-200 nm were made using high resolution e-beam lithography and reactive ion etching (RIE). The values of K{sub u} were measured by the GST method using the Anomalous Hall Effect; we observed the averaged signals of 6000 dots. The values of K{sub u} for dot arrays of 10-nm-thick L1{sub 1}-Co{sub 50}Pt{sub 50} films deposited on MgO(111) substrates (single crystal films) and glass disks (polycrystalline films) were nearly the same as those of the original films independent of D, indicating no significant etching damage by the RIE process. Magnetic force microscopy images revealed that all dots were single domains in the present D region. The coercivity H{sub c} of the dot arrays was 25.0 kOe [MgO(111) substrate, D=70 nm] and 14.3 kOe (glass disks, D=80 nm). The switching field distribution {sigma}/H{sub c} was relatively small, {sigma}/H{sub c}=0.15, even for dot arrays fabricated on glass disks, indicating the homogeneous formation of a L1{sub 1} type ordered structure in the Co{sub 50}Pt{sub 50} layers.

OSTI ID:
21190153
Journal Information:
Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 7 Vol. 105; ISSN JAPIAU; ISSN 0021-8979
Country of Publication:
United States
Language:
English