CGC perpendicular recording media with CoCrPt-SiO2 alloy as granular layer

Y. Sonobe, K. K. Tham, L. Wu, T. Umezawa, C. Takasu, J. A.H. Dumaya, T. Onoue, P. Leo, M. Liau

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


We investigated a new class of coupled granular/continuous (CGC) perpendicular media consisting of CoCrPt-SiO2 granular layer with magnetically decoupled small grains. By changing the number of Co/Pd bi-layers in the continuous layer, the degree of exchange coupling can be systematically controlled. The introduction of Co/Pd multilayer improved the nucleation field (Hn) from —570 to —1670 Oe and KuV/kBT values from 67 to 97. Compared to the base granular media, the CGC media had 1 dB gain in signal-to-noise ratio (SNR) as well as 14 dB gain in write-ability (OW). Moreover, the output decay was reduced from —0.11 to—0.035 dB per decade. In CGC approach, a more appropriate strength of exchange coupling can be introduced that yields the significant improvement in both SNR and thermal stability.

Original languageEnglish
Pages (from-to)2351-2353
Number of pages3
JournalIEEE Transactions on Magnetics
Issue number10
Publication statusPublished - 2006 Oct
Externally publishedYes


  • Continuous layer
  • exchange coupling
  • granular layer
  • perpendicular coupled granular/continuous (CGC) media
  • signal-to-noise ratio
  • thermal stability

ASJC Scopus subject areas

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


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