High-potential magnetic anisotropy of CoPtCr-SiO2 perpendicular recording media

T. Shimatsu, Hideo Sato, T. Oikawa, Y. Inaba, Osamu Kitakami, S. Okamoto, H. Aoi, Hiroaki Muraoka, Y. Nakamura

Research output: Contribution to journalArticlepeer-review

45 Citations (Scopus)


The magnetic anisotropy of CoPtCr-SiO2 perpendicular recording media, including higher energy terms, was studied as a function of film composition and seed layer materials. All series of CoPtCr films with various Cr content, deposited on Ru seed layers, show maximum values of total anisotropy Ku at 25-30 at%Pt. The maximum value for CoPt(Cr = 0) films reaches ~ 15 × 106 erg/cm3. The addition of SiO2 to the CoPtCr films reduces the grain Ku, however the grain K u maintains a large value of 8 × 106 erg/cm 3 even when 10at%SiO2 is added to (Co90Cr 10)80Pt20, for instance, which indicates the high-potential thermal stability. Theoretical calculations for media designs of 400 Gbits/in2 revealed that the ratio of the high-energy anisotropy term Ku2 to Ku1(Ku = Ku1 + K u2) is required to be 0.2-0.35 to enhance the energy barrier for the remanent state, without a notable change in switching field. The films deposited on Ru seed layers were found to show negligibly small Ku2 values, however, the values of Ku1 and Ku2 vary significantly with the seed layer material used. Ku1 decreases almost linearly as the Ku2 value increases. It is concluded that CoPtCr films have a sufficient potential in the values of Ku1 and Ku2 for high-density perpendicular media.

Original languageEnglish
Pages (from-to)566-571
Number of pages6
JournalIEEE Transactions on Magnetics
Issue number2
Publication statusPublished - 2005 Feb


  • CoPtCr-SiO
  • Magnetic anisotropy
  • Perpendicular recording media
  • Thermal stability

ASJC Scopus subject areas

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


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