By Topic

Characterization of the Reader Width Using the Micro-Track Test in Perpendicular Recording

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$33 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

6 Author(s)
Juan Fernandez-de-Castro ; Seagate Technology,, Bloomington,, MN, USA ; Gene Sandler ; Grace Le ; Pavol Krivosik
more authors

Micro-track test is a valuable tool used to characterize the electrical reader width in perpendicular recording. The test is based on trimming both sides of a track written with a single tone and followed by a cross-track scan of the remaining track. The reader cross-track profile or read sensitivity function is characterized by a narrow band measurement of the read-back signal as a function of cross-track position. With increasing track density, the signal amplitude decreases due to incomplete media saturation and to an increase in the off-track noise due to percolation and opposite polarity media saturation. These effects cause a lump at the edge of the micro-track profile that changes the width of the profile (MT10 and MT50). Micro-magnetic analysis indicates that the off-track demagnetization field creates a track-edge section in the media with opposite polarity relative to the originally written track. This section is coherent with the main track and decreases the read-back signal during the scan of the micro-track. Consequently, the shape of the cross-track read sensitivity function becomes distorted, causing a reduction in MT10 and a side lump. The solution to this problem is to increase the amplitude of the micro-track read-back signal by reduced trimming and by the use of a higher density (KFCI) in the main track that minimizes the off-track demagnetization field. These test improvements are shown to preserve the integrity of the micro-track profile and to enable an accurate measurement of MT10 and MT50. Optimizing reader and writer widths in perpendicular recording requires an accurate measurement of these parameters.

Published in:

IEEE Transactions on Magnetics  (Volume:48 ,  Issue: 7 )