Abstract
We investigated the noise reduction mechanism of a Cr-rich Co72Cr28 perpendicular magnetic recording medium. By increasing the Cr content from 22 at% to 28 at%, the signal-to-noise ratio at a recording density of 70 kFCI was increased from 25 dB to 31 dB. The medium noise was reduced more than the magnetic parameters, such as MS and HC⊥. When the average crystalline diameter of the media increases, the medium noise of the Cr 28 at% medium does not increase, whereas that of a Cr 22 at% medium increases. Analysis of a medium with a Ti under-layer shows that the Δθ50 does not have any significant effect on the medium noise. To analyze the noise of these media, we introduced ΔM⊥ measurement method that takes account of the demagnetization field. The ΔM⊥ value is related to the medium noise. The relation is different from that of longitudinal medium. Analysis of the minor loops showed that the Cr 28 at% medium has low noise due to its highly stable dc-erased state. MFM observation for 4-μm-wide dc-erased tracks confirmed the mechanism for smaller reversed magnetic domains in a Cr 28 at% medium than in a Cr 22 at% medium. This mechanism contributes to the low noise of the Cr-rich Co-Cr single-layer perpendicular medium.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
