Perpendicular recording media

Double-Layered Zl0 FePtrC/FeCoNi Perpendicular Recording Media... 

Figure 6. Schematic presentation of longitudinal and perpendicular recording media.

In the case of perpendicular recording media the device consists of recording layer with a perpendicular anisotropy, a soft magnetic underlayer (SUL), and an intermediate layer. The SUL is essential for improving the performance of perpendicular recording media. Electroless deposition is very suitable for the production of SUL. 

For the media preparation, 25-nm-thick CoZrNb soft magnetic film was sputtered onto Ni-P SUL and then a thick CoPtCr-SiC>2 granular recording layer. For comparison, a media with 200-nm-thick sputtered CoZrNb SUL was used. The results showed that an electroless-deposited ferromagnetic Ni-P layer (low phosphorus content), which is suitable for mass production as a SUL for a double-layered perpendicular recording media, exhibits almost the same magnetic properties and recording performances as a 200-nm-thick sputtered SUL. In addition, the spike noise which is commonly observed from SUL was not found for the media with Ni-P SUL. 

Osaka T et al (1990) High density perpendicular recording media by an electroless plating method. ITEJ Tec Rep VIR90-29 l-9... 

Tanahashi K et al (2002) Low-noise EeTaC underlayer for double-layered perpendicular recording media. J Magn Magn Mater 242-245 325-327... 

Sugiyama A (2005) Electroless deposition of soft magnetic underlayer for a double-layered perpendicular recording media. lEICE Tech Rep MR2004-48 15-20... 

Figure 4 TEM of platelike barium ferrite particles for perpendicular recording media. He = 750 Oe. (Courtesy of Horiishi, Toda Kogyo Corp., Hiroshima, Japan.)...

Tanaka M et al (2005) Microstructure of a Co/Pd multilayered perpendicular recording medium with Pd seeds prepared by electrochemical process. J Magn Magn Mater 287 188-192... 

Fig. 8. The main-pole driven head in combination with a Co—Cr/Ni—Fe double-layer medium for perpendicular recording.

In a double-layered perpendicular magnetic medium, an intermediate layer between a recording layer and an SUL plays an important role as a seed to control the crystal growth of the recording layer and to reduce the magnetic domain size of the recording layer. Moreover, the intermediate layer should be as thin as possible to minimize the... 

Perpendicular Magnetic Recording Medium for a Density Beyond 1 Tera Bit/inch ... 

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