DocumentCode :
3602864
Title :
An Experimental Investigation on Curie Temperature Variations and Related Switching Field Distributions in Heat-Assisted Magnetic Recording Media
Author :
Chen, Y.J. ; Leong, S.H. ; Yang, H.Z. ; Hu, J.F.
Author_Institution :
Data Storage Inst., Agency for Sci., Technol. & Res., Singapore, Singapore
Volume :
51
Issue :
11
fYear :
2015
Firstpage :
1
Lastpage :
4
Abstract :
The signal-to-noise performance of heat-assisted magnetic recording (HAMR) is closely related to media magnetic and thermal property distribution, especially with the grain-to-grain variations in Curie temperature (Tc) or Tc distribution (σTc). In this paper, we report an experimental study on Tc variations and related switching field distributions (SFDs) in FePt-based granular HAMR media by a new measurement method using two laser beams [one pump beam for heating and one probe beam for magnetooptical Kerr effect (MOKE) signal detection] and a small perpendicular ac magnetic field (Hsw) applied to the laser heated media. The measured MOKE amplitude (or magnetization) changes with laser power (or media temperature) shows a peak at around Tc, while the full-width-at-half-maximum (FWHM) of the peak is related to the media Tc variations and SFD. The peak position is observed to shift to lower laser power (or media temperature) with broadened FWHM and SFD for larger Hsw. It is demonstrated that the proposed method, being consistent with previous measurement results, is fast and nondestructive. The experimental measurement method and results could provide us quantitative estimations and insights for Tc variations and SFD in HAMR media.
Keywords :
Curie temperature; Kerr magneto-optical effect; magnetic recording; Curie temperature; FWHM; full-width-at-half-maximum; grain-to-grain variations; heat-assisted magnetic recording media; laser beams; magnetic field; magnetooptical Kerr effect; probe beam; pump beam; signal-to-noise performance; switching field distributions; thermal property distribution; Heat-assisted magnetic recording; Laser excitation; Magnetic field measurement; Measurement by laser beam; Media; Power lasers; Temperature measurement; Curie temperature ( $T_{c}$ ) distribution; Curie temperature (Tc) distribution; heat assisted magnetic recording (HAMR) media,; heat-assisted magnetic recording (HAMR) media; magneto-optical Kerr effect (MOKE); switching field distribution (SFD);
fLanguage :
English
Journal_Title :
Magnetics, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9464
Type :
jour
DOI :
10.1109/TMAG.2015.2438004
Filename :
7118720
Link To Document :
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