Magnetic medium

The electron beam is very well suited for the production of most of the magnetic media, such as high-density floppy disks and magnetic tapes. In 

Most of the EB units sold in the recent past were mainly for release coating applications. New chemistry has been commercialized, but further developments are needed to satisfy this market segment.  

Another process where electron beam equipment is widely used is curing of overprint varnishes (OPVs). OPV is applied over a printed surface to protect the ink layer and to improve the appearance of the product. The exceptionally high gloss of such finishing coatings and varnishes is achieved specifically by EB cure.  

Typical applications of EB curing in protective and decorative coatings 

Elec Iron beam processor for curing coatings. HVPS, high-voltage power supply. The arrow in the EB curing unit indicates the direction of the electron beam. (Courtesy Energy Sciences, Inc.) 

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Optical media have the capacity to handle much larger amounts of digiti2ed information than equivalent si2es of magnetic media. These capacities... 

The most important mass memories use magnetic media in the form of magnetic tapes or disks (floppy disk and hard disk). Laser addressed optical mass memories are of increasing commercial importance. 

Erasable optical disk (EOD) systems, on the other hand, are challenging classic magnetic media in some areas of appHcation, primarily magnetic tape and the hard disk, but mostly optical media complement magnetic media. 

There is no competitive situation for data storage disks with embossed iaformation (CD-ROM) and recordable/nonerasable disks (WORM) no counterpart to CD-ROM and WORM exists among magnetic memories. EOD drives are best compared to floppies and removable hard disk media given their possibiUty of easy and problem-free disk exchange and a capacity on the order of that of removable magnetic media (Tape, Bernoulli, SyQuest). 

Magnetic Discharge Kate. In order to maintain high magnetic media recovery, the magnetic discharge rates should not exceed 9 MTPH/m for 762 mm dia dmms or 15 MTPH/m for 914 mm dia dmms. 

Figure 5 Bragg>Brentano diffraction pattern for magnetic media used in a demonstration of 1-Gb/in magnetic recording. The iines show a deconvoiution of the data into individual diffraction peaks, which are identified.

Magneto-optic and magnetic disc materials DyCo, TbFeCo, garnets, sputtered magnetic media (CoNiCr alloys and their carbon overcoats). 

An imponant component of the complex metallizations for both semiconductor devices and magnetic media is the diffusion barrier, which is included to prevent interdiffiision between layers or diffusion from overlyii layers into the substrate. A good example is placement of a TiN barrier under an Al metallization. Figure 7a illustrates the results of an SNMSd high-resolution depth profile measurement of a TiN diffusion barrier inserted between the Al metallization and the Si substrate. The profile clearly exhibits an uneven distribution of Si in the Al metallization and has provided a clear, accurate measurement of the composition of the underlying TiN layer. Both measurements are difficult to accomplish by other means and dem-... 

The submissions of section 313 reports in magnetic media and computer-generated facsimile formats has been approved by EPA. Magnetic media submissions to EPA must follow basic specifications set forth by EPA in the document. Magnetic Media Submissions Instructions fEPA 560/4-90-008) which is also included in EPA s Toxic Chemical Release Inventory Reporting Package for 1989 (EPA 560/4-90-001). To order these documents, see the document request form in Appendix I. 

The term document should be taken to include data or any information that is recorded and stored either on paper or magnetic media in a database or on disk. It may be... 

The most significant development in Japan is the entry of photographic film companies (Fuji and Konishuroku) into the manufacture of magnetic media. They are having a large impact because the heart of the manufacturing process... 

A challenge related to the problems of reactor design and engineering is the modehng and study of the fundamental chemistry occtrrring in manufactrrring processes for semiconductors, optical fibers, magnetic media, and interconnection. 

Klaus, E. E. and Bhushan, B., "Lubricants in Magnetic Media-Review, Tribol. Mech. Magn Storage Syst., Vol. 2, 1985, pp.7-15. 

Depth profiling may be conducted on insulating materials, and XPS can perform thickness measurements on organic films such a lubricants on magnetic media. It is capable of measuring surface contamination by both inorganic and organic materials on a wide variety of substrates. 

Most published work has focused on the deposition of Ni, Co, and NiCo alloys from hypophosphite electrolytes [14], and this part of the review will deal primarily with these alloys. Other Co alloys studied include CoZnP [15, 16], the recording characteristics of which were described by Soraya [17] CoSnP [18], which is reported to have enhanced corrosion resistance and the rhenium and manganese alloys used for vertical recording, discussed below. Other reductants, such as hydrazine [19], dimethylamine borane [20-22], pyridine borane [23], and borohydride [24, 25], can be used for the chemical deposition of nickel and cobalt, but to date there has been no significant application of these to the technology of magnetic media. 

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