The exact manufacturing process of perpendicular recording media is unsurprisingly a closely guarded secret, especially considering its recent arrival on the marketplace. From patents filed at the United States Patent and Trademark Office (USPTO), it can be taken that the predominant technique involves the laminating of magnetic and non-magnetically charged metals such as chromium, cobalt, platinum and alloys of similar; sandwiching unique layers to affect the desired result – a recording medium such that the magnetic particles are aligned perpendicular to the platter. In US patent number 6387483, filed by the NEC Corporation of Tokyo; it describes the technique as follows:The perpendicular magnetic recording medium of the embodiment is formed by laminating a Cr film, a soft magnetic under layer film, and a perpendicular magnetizing film on a substrate in this order. (Source: USPTO no. 6387483)

In longitudinal media manufacture too, laminating multiple supportive metals is achieved; in perpendicular media however, the difference is the magnetizing film as described above. Whereas traditional lamination ordinarily serves only to prevent wear and noise (both electro-mechanical and audible noise), in perpendicular media manufacture it would appear that at least some of the lamination process is used to magnetize the magnetic media particles to a perpendicular orientation. Precisely how the reorientation of magnetic media particulate is accomplished is not easy to determine, most probably because the technology is so new that such details are sketchy at best and obscure or guarded at worst. This fact is not at all surprising concerning a new technology such as perpendicular magnetic media development.

The Future of Storage Technology

Perpendicular magnetic media technology as discussed earlier is merely a temporary solution, to find more permanent solutions we must look to much more advanced technologies. One such technology is patterned magnetic media. The process of patterned magnetic media aims to make singular magnetic particulates the object of recording bits, you will remember that current technologies requires approximately 500 to 1000 magnetic particles to store a single bit. The object of patterned media is to cut this dramatically down to a single particle per bit. Advantages of such a technology are such as reduced statistical noise associated with granular media and more increased areal density (as much as 64Gbit/inch2).

Patterned magnetic media aims to prevent the SPE barrier, or at least further decrement its effect through the use of so-called mesas and valleys. The technique uses the creation of barriers between magnetic particles, thereby avoiding the SPE complication which affects closely packed particles. Holographic Storage (a.k.a. Holographic Lithography) too is a technology that aims to increase storage capacity which is also under heavy research, and claims to be a much more permanent solution. Unlike Patterned Magnetic Media, Holographic Storage is a revolutionary step away from magnetic media and previous optoelectronic technologies.

Hard Disk Drives will always be subject to inertia and centrifugal force induced by the moving parts of the drives mechanical components (platter, read/write head), Holographic Storage has no such issues; the holographic process uses lasers in replacement of the read/write head of a Hard Disk Drive and the media itself requires no momentum (unlike the platters in Hard Disk Drives).

Such holographic storage is far from realisation, in fact it is postulated by some that it may be as much as ten years before the technology can be made into a workable solution. In direct symmetry to early memory research, research on Holographic Storage technologies seems to have banded into two camps: one of super fast data retrieval and extraordinarily high capacity storage; no doubt there will be extremely profitable markets for both.

Sean Nicholls is an undergraduate at the National College of Ireland where he is working on a Bsc.H in Software Systems. With almost six years experience of Computer Programming, Sean has extensive knowlege of computers and computer-related technology.