Scratch-induced demagnetization of perpendicular magnetic disk

Masaru Furukawa, Junguo Xu, Yuki Shimizu, Yukio Kato

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)


The mechanism of scratch-induced demagnetization was studied in perpendicular magnetic recording (PMR) disks. These scratches, which may occur on the disk's surface during head/disk contact, cause demagnetization that results in read/write errors. The scratchinduced demagnetization is thus investigated by the scratch test, observation of atomic force microscopy and magnetic force microscopy, and analysis of transmission electronic microscopy. It was found that the angle of the grain in the recording layer, which is vertically orientated on a PMR disk, was tilted under the scratch. These analyses revealed that scratch-induced demagnetization is caused mainly by plastic deformation which results in grain tilt in the recording layer, rather than by stress. Therefore, a dense and not-easily titled grain structure in the recording layer is needed to produce a reliable hard disk drive (HDD).

Original languageEnglish
Pages (from-to)3633-3636
Number of pages4
JournalIEEE Transactions on Magnetics
Issue number11 PART 2
Publication statusPublished - 2008 Nov
Externally publishedYes


  • Demagnetization
  • Head-disk interface (HDI)
  • Perpendicular magnetic recording (PMR)
  • Scratch

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering


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