Perpendicular magnetic recording

It is of technological interest to grow fUms/multilayers that are spontaneously magnetized perpendicularly to the film plane. This could increase the density of data storage, which is important in magnetic recording. Perpendicular magnetization in thin films can be achieved because of a positive (i.e., perpendicular) interface or volume anisotropy. 

FLUORINECOMPOUNDS,ORGANIC - FLUORINATED ACETIC ACIDS] (Volll) Perpendicular magnetic recording... 

Fig. 33—Magnetic recording technologies longitudinal versus perpendicular recording.

The magnetic properties of Co/Pt MLs depend on the thicknesses of the individual layers, /p and tCo (57). For tCo <1.2 nm, the axis of easy magnetization is perpendicular to the surface, as desired for MO recording. The maximum anisotropy is found for tCo = 0.4 nm, corresponding to two atomic layers. Square hysteresis loops with 100% remanence are observed for tCo < 0.5 nm and a total ML thickness of about 20 nm. A practically used configuration is, eg, 14x (0.4 nm Co +1.2 nm Pt). The information in these media is magnetically stored in about 30 layers of magnetic Co atoms. 

Barium ferrite adequate for certain permanent magnet applications can be prepared from crude mineral iron oxide. A past interest in the material for perpendicular magnetic recording stimulated studies of a variety of chemical routes, including hydrothermal synthesis, to produce powders [12]. 

Electroless Cobalt Alloys for Perpendicular Magnetic Recording Media. 82... 

CoNiReMnP showed that addition of certain complexing agents as well as addition of MnS04 controls the c-axis orientation. Table 8 lists typical bath compositions and conditions of electroless cobalt alloy plating for perpendicular magnetic recording media. 

Table 8. Bath compositions and operating conditions for electroless-plated perpendicular magnetic recording media (T. Osaka et al., 1991 [116]).

Liu T, Liu T (1991) Loess, Environment and Global Change. Science Press Beijing, China Lodder JC (1995) Magnetic microstructures of perpendicular magnetic-recording media. Mater Res Soc Bull, October 1995 59-63... 

Currently it appears that further research on electrochemical deposition of magnetic thin films is of academic interest only. This research can be very useful in developing new structures and new ideas that can be later adopted by physical techniques of deposition. Recent developments in this area include work on longitudinal and perpendicular magnetic recording media [158,159]. 

Tanaka Y (2005) Recording performance and system integration of perpendicular magnetic recording. J Magn Magn Mater 287 468-474... 

Magnetic Thin Films for Perpendicular Magnetic Recording Systems... 

Soft Magnetic Underlayer by Electroless-Deposition for Perpendicular Magnetic Recording... 

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