Three Advances Make Magnetic Tape More Than a Memory

Scientists at Sony and IBM have developed magnetic tape on which they can now store 201 gigabits per square inch. One cartridge stores a kilometer of the tape; this one palm sized cartridge, could hold 330 terabytes of data, or roughly 330 million books’ worth. This is the largest drive ever created, even larger than Seagate's solid-state drive and IBM's best commercial tape. Hard disks are reaching the end of their capacity due to their inefficiency and expensive price. IBM sees a great business opportunity in tape storage because so far there is nothing that can compete with it. 

How it works and what has improved
An electro magnet called a write transducer magnetizes tiny regions of the tape so that the magnetization field of each region points left or right, to encode bits 1 or 0. IBM has increased tape drive density by shrinking the magnetic regions as well as the read/write transducers and the distance between them, reducing cost per gigabyte. 

The surface of the tape is painted with a magnetic material, where Sony has now developed a new technique called "sputtering" to coat the tape with a multilayer magnetic metal film. This new film is thinner and has narrower regions, allowing more bits in the same tape area.

The IBM team also decreased the width of the tape reader to 48 nm and added a think layer of a highly magnetized material yielding a stronger magnetic field. Sony also added an ultrathin lubricant layer on the tape surface to avoid friction.