IBM's new technology to quadruple disk drive density

Armonk, May 

IBM today announced that it is using just a few atoms of

‘pixie dust’ to push back the data storage industry's most formidable

barrier. The company is the first to mass-produce hard disk drives using a

revolutionary new type of magnetic coating that is eventually expected to

quadruple the data density of current hard disk drive products–a level crucial

for the burgeoning Internet economy. For consumers, increased data density will

help hasten the transition in home entertainment from passive analog

technologies to interactive digital formats.

The key to IBM's new data storage breakthrough is a

three atom thick layer of the element ruthenium, a precious metal similar to

platinum, sandwiched between two magnetic layers. As only a few atoms could have

such a dramatic impact caused some IBM scientists to refer to the ruthenium

layer informally as ‘pixie dust’.

Known technically as ‘antiferromagnetically-coupled

(AFC) media,’ the new multilayer coating is expected to permit hard disk

drives to store 100-gigabits of data per square inch of disk area by 2003. AFC

media is now shipping in IBM's Travelstar notebook hard disk drive products with

data densities up to 25.7 gigabits per square inch. In time, IBM plans to

implement AFC media across all of its disk drive product lines.

The increasing data densities enabled by AFC media are

expected to simplify processes for storing consumers' rapidly growing volumes of

digital data; accelerate an industry trend toward smaller disk drive form

factors that consume less energy; and stimulate the creation of new and more

capable digital-media and data-intensive applications.

“AFC media is the first dramatic change in disk drive

design made to avoid the high-density data decay due to the superparamagnetic

effect,” said Currie Munce, Director (Advanced Hard Disk Drive Technology),

Storage Technology Division, and Director (Storage Systems and Technology), IBM.

“Our deep understanding of the complex physical phenomena of how the AFC media

works enabled us to be first in the industry to ship AFC media in products, and

we are working to extend this technology to perform magnetic recording at

100-gigabits per square inch and beyond.”

The 100-gigabit density milestone was once thought to be

unattainable due to the superparamagnetic effect. A natural solution to this

problem is to develop new magnetic alloys that resist more strongly any change

in magnetic orientation. But recording data on such materials becomes

increasingly difficult.

AFC media solves this problem. The ultra-thin ruthenium

layer forces the adjacent layers to orient themselves magnetically in opposite

directions. The opposing magnetic orientations make the entire multilayer

structure appear much thinner than it actually is. Thus small, high-density bits

can be written easily on AFC media, but they will retain their magnetization due

to the media's overall thickness.