Composite Structure With Superparamagnetic Writing Layer for Heat-Assisted Magnetic Recording

• Published in: IEEE transactions on magnetics Vol. 52; no. 7; pp. 1 - 4
• Main Authors: Zengyuan Liu, Victora, R. H.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.07.2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Analytical models; Composite Media; Composite structures; Cooling; Ferrous alloys; Heat Assisted Magnetic Recording; Iron compounds; Magnetic recording; Magnetism; Mathematical analysis; Mathematical model; Platinum compounds; Probability distribution; Recording; Superparamagnetic Writing; Switches; Variance; Writing; superparamagnetic writing; Composite media; heat-assisted magnetic recording (HAMR)
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2016.2520362

In conventional heat-assisted magnetic recording media, the recording layer also acts as the storage layer. To minimize the effect of Tc variance, a new composite structure with a superparamagnetic writing layer is proposed to decouple the recording problem from the long-term storage issue. The thermal switching probability distribution (SPD) was calculated using 1 nm × 1 nm × 1 nm renormalized parameters of FePt. Analytical derivation and micro-magnetic simulation results both show the volume dependence of the SPD: Width ∝ 1/(Volume) 1/2 . The SPD of the composite structure designed in this paper has a full-width half-maximum of 44 K, which is 20% narrower than that found in an FePt recording layer subject to 3% Tc variance.