
ATOMM stands for Advanced super-Thin layer and high- Output Metal Media. It is an ultra-high-density recording media consisting of a super-thin layer of metal particles coated over a non-magnetic layer of titanium compound. Ordinary magnetic media consists of a magnetic coating on a basefilm substrate. ATOMM technology, on the other hand, is a dual-coating technique that deposits TWO layers on the basefilm. The lower layer is a titanium compound (titan-fine) that improves durability. The upper layer is a remarkably thin layer (0.1 to 0.5 "microns" - millionths of a metre!) of magnetic particles that allows superior high-density recording.
To appreciate how thin the magnetic layer is, make a dot with a pen or pencil. That dot, which is about half a millimeter in size, can hold approximately 10,000 ATOMM magnetic layers within its width. The two layers, magnetic on top of non-magnetic, are simultaneously coated onto the basefilm. This exclusive dual-coating system is the heart of ATOMM technology.
Second-generation ATOMM-II technology has enabled even higher-density recording of signals, using smaller magnetic particles packed in an ultra-thin magnetic layer.
The conventional method used to coat magnetic media involves roll coating a magnetic layer onto the basefilm. This method has definite limitations as to how thin the coating can be, thus preventing advances to higher-density recording.
Another coating method is Metal Evaporated (ME), which allows the deposition of very thin magnetic layers for high-density recording. The ME process, however, must be carried out inside a vacuum chamber with very high heat. It is, therefore, relatively cost inefficient.
To overcome these limitations, Fujifilm developed a new technology - simultaneous dual-coating - using the slot die coating method to put ATOMM's two layers on the basefilm. The Fujifilm coating head applies two separate formulation layers simultaneously at different depths and thicknesses. The dispersion for the lower layer from one slot carries the thinner upper layer from the second slot on top of it.
This provides the following advantages:
High frequency recording signals are shorter wavelength signals. With these signals, however, a thicker magnetic layer (with more magnetic depth) has a demagnetizing effect. (It's harder to magnetize an object thicker than one-third the bit wavelength.) Therefore, for higher density recording, the thinner the magnetic layer, the better. Whereas an ordinary high-density floppy disc has a magnetic coating 2 to 5 microns thick; the coating of an ATOMM disc is 0.1 to 0.5 microns. This means ATOMM's magnetic layer provides better signal strength (higher output) and a better S/N ratio for higher density recording. In fact, the ATOMM disc provides 8dB higher signal output -- a signal that is 250% stronger when compared to a conventional high-density disc.
A smooth surface is very important for magnetic recording media. Rough surfaces produce weaker magnetism due to magnetic separation and provide poor S/N ratios. ATOMM's dual-coating process results in a glossy, extremely smooth recording surface, due in large part to the minute spherical particles in the "titan-fine" lower layer. These particles are about one-sixth the size of ordinary metal magnetic particles. The resulting smoothness of the super-thin upper layer results in lower noise, fewer dropouts and better durability.
As mentioned above, the smooth surface of the ATOMM media results in less wear for longer durability. In addition, the three-dimensional network binder in the upper layer improves stability and durability during high-speed operation. Performance is also enhanced by lubricants, which are optimized in both the upper and lower layers. Furthermore, the lower layer acts as a reservoir for lubricants, which can complement the supply to the upper layer when required. Finally, the cushioning effect from the lower layer provides improved head-to-media contact and durability.
ATOMM employs a high molecular weight binder that resists time fatigue and environmental effects. Its magnetic particles are also more stable than those in conventional media. In accelerated aging tests, ATOMM media demonstrated significant advantages over single-layer media.
Fujifilm's exclusive dual-coating method applies the two layers to the basefilm simultaneously. The efficiencies of mass production minimize the cost of the product. Compared to other types of media, even ME media, ATOMM's combination of advantages, makes it the perfect choice for high-density data recording.
In 1999, the DDS-4 was released, again exploiting ATOMM's high-density recording potential to yield 20GB native on a single 4mm-wide tape cassette. A Fujifilm professional digital audiocassette for the DTRS system also uses ATOMM double-coating technology.
More recently, ATOMM has been adopted for use in all three generations of the LTO (“Linear Tape Open”) format. Generation-1 tapes had a native capacity of 100 GB (200 GB compressed), Generation-2 had a native capacity of 200 GB (400 GB compressed), while Generation-3 cartridges, introduced at the end of 2004, provide an amazing 400 GB native (800 GB compressed).
Super DLT II cartridges have attained 300 GB native capacity, 600 GB compressed, utilizing an ATOMM formulation.
Undoubtedly, Fujifilm ATOMM media will lead to more advances in new generations of existing formats as well as in completely new formats in the years to come. Fujifilm’s exciting NANO CUBIC technology, announced in 2001, employs nano technology techniques to achieve another leap in magnetic media capacity. In 2002, IBM demonstrated that a terabyte (TB) of data could be written to one cartridge containing NANO CUBIC tape.
