IBM announced Monday that it has begun mass-producing a magnetic coating technology that will eventually allow a quadrupling of the amount of data that can be stored on a single hard disk. The new technology will permit hard disk drives to store 100 gigabits of data per square inch of disk area by 2003, according to IBM. That would translate into desktop computers with 400GB hard drives and the ability for handheld devices to store as much as 6GB of video data, or the equivalent of eight movies. IBM said the technology, antiferromagnetically-coupled (AFC) media, sandwiches a three-atom-thick layer of a precious metal similar to platinum between two magnetic layers on a disk. Because of its atomic size, scientists at IBM have dubbed the metal "pixie dust." Bob Scranton, director of recording-head technology at IBM's Almaden Research Center in San Jose, said AFC media breaches a wall that the industry once believed unpenetrable due to the "superparamagnetic effect," or high-density data decay, which was thought to appear when densities reached 20 to 40 gigabits per sq inch "What scientists have known for some time is that as you decrease the volume of magnetic grains you're writing on, at some point, you'd get to where the volume of grain is so small it can't hold magnetization over the product's life span," Scranton said. Because of that limitation, other storage technologies such as optical disks appeared to be more promising than magnetic disks, which are the current industry standard. "If this is truly a quadruple leap forward, it could only solidify [the] disk's place in a storage environment," said John Madden, an analyst at Summit Strategies in Boston. Initially, IBM is using the AFC media in its Travelstar notebook hard disk drive products. Currently, it allows data densities up to 25.7 gigabits per square inch. The AFC media is the first product of its type to be mass-produced, according to Madden. Not only do the new disks promise to decrease the footprint of data storage systems, but by increasing data density, disks will be made lighter and consume less energy, according to IBM.