Hard disks, magnetic

The application of the cyclophosphazene N3P3(OC6H4F-4) (OC6H4CF3-3)e (n 2 code name X-IP) as a lubricant is well known. Comparative studies of the tribological properties of X-IP and ionic liquids of al-kylimidazolium tetrafluoroborates have shown a preference for the tetrafluo-roborates as lubricants. The interaction of X-IP with a carbon-coated head at the head-disk interface of hard disk magnetic storage systems in the presence of a perfluoropolyether (PFPE) lubricant, has been diseussed. Attention has been paid to the application of a novel lubricant (A20H) which consists of (234) as the major component and small quantities of (235). The new lubricant displays a lower mobility on carbon surfaces than hydroxyl-... 

Hard disk magnetic storage hard drives consist of rigid circular disks with diameters that range between about 65 mm (2.5 in.) and 95 mm (3.75 in). During read and... 

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. 

MO Media Summary. When compared to magnetic recording on hard disks, the advantage of MO data storage is the removabiUty of the disks and the high storage capacity (especially on multiplatter (juke-box) systems) whereas the access times have not yet been reached. 

An advantage of aluminum is the high level of knowledge and the automated production plants stemming from the mass production of A1 substrates for magnetic hard disks these can be widely used for the production of substrate disks for optical data storage. 

The question as to whether and to what extent and in what area optical mass storage would replace magnetic systems (disk, tape) was controversially being discussed in the 1980s. In spite of all predictions of an imminent substitution, as of late 1994 magnetic hard disks stiU are the system of choice for computer-dedicated mass storage due to their speed (access time, transfer rate), physical size, and energy consumption this is especially tme when memory-intensive appHcations are mn which use the hard disk as virtual memory. 

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). 

Tribology performances and applications of ordered molecular films have been a long-standing research subject in SKLT, the workplace for the authors of this book. Hu and Luo [42] prepared SAMs of fluoroalkylsilane (FAS) and poly-fluorealkylmethacrylate (PFAM) on the magnetic head of computer hard disk drivers. Experiment results show that the molecular films greatly improve the performance of the... 

This chapter introduces three kinds of surface organic modihcation hlms on a magnetic head that we have studied. These are polyfluoroalkylmethacrylate films, X-1P films, and self-assembled monolayers (SAMs). It also reviews the works of surface lube on a hard disk surface. In the last, the challenges on the development of a magnetic recording system are discussed. 

Partially fluorinated X-IP has been used for a number of years as an additive in the inert lubricant PFPE film on the surface of a magnetic hard disk to enhance start/stop durability of PFPE lubricants [29,30]. Recently it has been used as a vapor lubricated film on the surface of the disks [31 ]. In order to avoid the PFPE being catalyzed to decomposition by the slider material AI2O3 (refer to Section 3.4), XI -P was also examined as a protective film on the surface of the magnetic heads [25,32]. The results of CSS tests indicate that the thermal stability of the lubricant was greatly improved in the presence of X-1P, and the thickness of X-1P film on the slider surface has an important influence on HDD lubrication properties. 

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