Properties of lithographically formed cobalt and cobalt alloy single crystal patterned media

Ganesan, S.; Park, C.M.; Hattori, Katsumi; Park, H.C.; White, Robert L.; Koo, Hyun Cheol; Gomez, R. D.

doi:10.1109/20.908650

Cited by 12 publications

(5 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Appropriate high anisotropy materials then allow stable particle dimensions of the order of 2 nm potentially enabling areal densities in excess of 40 Tbit in −2 with no transition noise. Worldwide research efforts to realize media of this type are predominantly exploring two principal strategies: (a) patterned media produced using lithographic and/or etching processes [5] and (b) self-assembling arrays produced via complex chemical or biological synthesis routes [6][7][8][9][10][11]. Neither of these techniques is readily compatible with production methods currently employed by the recording industry and both have so far failed to deliver media uniformity over any technologically useful area.…”

Section: Introductionmentioning

confidence: 99%

Fabrication and characterization of nano-particulate PtCo media for ultra-high density perpendicular magnetic recording

et al. 2007

View full text Add to dashboard Cite

The year-on-year growth in areal recording density maintained now for half a century by the hard disk industry has required a corresponding reduction in the size of the magnetic grains comprising the storage media employed. Grain dimensions are now such that the performance of materials which thus far have served the industry well can no longer be maintained as further reduction in their volume risks breaching the superparamagnetic limit with the attendant loss of data integrity. The high magnetocrystalline anisotropy of the Ll0 phase of PtCo allows particles as small as 4 nm diameter to remain magnetically stable in the elevated temperature environment typical of disk drive systems. A non-interacting dispersion of nanomagnetic particles suspended in an inert non-magnetic host such that each has its anisotropy axis directed perpendicular to the surface of the medium now constitutes the new ideal for a recording medium. Fabrication by a novel combination of conventional sputtering and thermal processing technologies of a medium closely approximating this ideal is demonstrated. An optimized two-stage fabrication process produces a near mono-dispersion of particles with magnetic activation volumes centred about 5 × 10−26 m−3 and crystallized in the L10 phase with an orientated tetragonal structure. The characteristics of this medium are discussed as a function of composition and crystalline structure. In the absence of a thermally assisted recording head, experiments are conducted on a degraded form of the medium that is shown to support perpendicular recording at linear densities in excess of 240 kfci (D50 point).

show abstract

Section: Introductionmentioning

confidence: 99%

Fabrication and characterization of nano-particulate PtCo media for ultra-high density perpendicular magnetic recording

et al. 2007

View full text Add to dashboard Cite

show abstract

“…Magnetic defects were observed as the spread switching field distribution for dot arrays [5], [6]. Many factors of switching field distribution have been considered, i.e., materials of continuous film [7], difference of the size of grains contained inside the dot [8], and dot shape.…”

Section: Introductionmentioning

confidence: 99%

Patterned Media Fabricated by Lithography and Argon-Ion Milling

2004

View full text Add to dashboard Cite

Using continuous film prepared by lower gas sputtering, a dot array with a more stable single domain was achieved. The requirements for magnetic properties of patterned media were different from that of perpendicular continuous-film media. The switching field distribution in dot arrays depends on fluctuation in dot size. The smallest size of dot arrays, fabricated by most simple method as lithography and ion-milling, is 50 nm.

show abstract

“…However, a magnetization-switching field H s of each dot is difficult to control and, in fact, a large dispersion of H s is reported in the patterned media so far. The dispersion of H s in dot-arrays was considered to arise from the spatial dispersion of magnetic easy axis, fluctuation of dot shape and the magnetostatic interaction among the dots [3][4][5]. In this paper, the magnetization reversal process in CoPt dot-array has been studied by magnetic force microscope (MFM) to make clear the mechanism for H s -distribution in dot-arrays.…”

mentioning

confidence: 98%

“…An incoherent magnetic rotation may be responsible to the magnetization reversal in the present dot-array. Previous experimental and simulation studies on magnetization reversal process in dot-array revealed that H s reduced extremely from H k through the formation of intermediate multi-domain state [4] or vortex state [9]. The magnetization of cubic corner easily reverses because of shape effect [10].…”

mentioning

confidence: 99%