KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Filters

20191

Settings

Author: search.filters.author.Tipcharoen, W.Subject: search.filters.subject.FePt

Search Results

Now showing 1 - 1 of 1
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Composite media with reduced write temperature for heat assisted magnetic recording
    (2019-09-15)
    Natekar, N. A.
    ;
    Tipcharoen, W.
    ;
    Victora, R. H.
    A major issue plaguing Heat Assisted Magnetic Recording (HAMR)is the high writing (T<inf>write</inf>)and peak heat spot temperatures (T<inf>peak</inf>). To counter this, a low temperature thermal exchange coupled composite (ECC)media with reduced write temperature relative to previous high temperature thermal ECC media is introduced. The FePt T<inf>c</inf> is reduced from 700 K to 500 K, and the write layer T<inf>c</inf> is reduced from 900 K to 600 K. Optimizations for M<inf>s</inf> and K<inf>u</inf> of the write layer generate values of M<inf>s</inf> = 700 emu/cm<sup>3</sup> and K<inf>u</inf> = 1.0 × 10<sup>7</sup> erg/cm<sup>3</sup> at 300 K. Switching Probability Distribution (SPD)calculations with lowered T<inf>peak</inf> = 650 K indicate T<inf>write</inf> = 487 K. This indicates a T<inf>write</inf> reduction by 34% as compared to the previous write temperature of 738 K for the high temperature thermal ECC media. Examining the FWHM of the SPD under 0% and 3% T<inf>c</inf> variation indicates a noise reduction of ∼20% relative to single layer high T<inf>c</inf> FePt media, and a much larger reduction relative to low T<inf>c</inf> FePt media. The jitter values at lowered T<inf>c</inf> approach the ideal value set by the grain size in the absence of any T<inf>c</inf> and K<inf>u</inf> variation. Simulations with uncorrelated and correlated T<inf>c</inf> and K<inf>u</inf> variations in the write and FePt layer generate similar results. Reduction of FePt T<inf>c</inf> may reduce the anisotropy relative to its undoped value: reduction of anisotropy by 33% is found to adversely affect the SPD by only 3–4%, but has a larger impact on jitter. These results help establish the usefulness of a low temperature thermal exchange coupled composite media for HAMR.