TOKYO—Sony said it has developed a super-dense data tape capable of recording more than 185 terabytes per cartridge. The tape, tested in conjunction with IBM, will be introduced at the INTERMAG Europe 2014 international magnetics conference to be held in Dresden, Germany beginning May 4.
Sony said its new tape has the highest areal density of any available on the market at 148 Gb per square inch, about 74 times that of an LTO-6 Ultrium cartridge. It said LTO-6 high-end LTO Ultrium format data cartridges have an areal recording density of approximately 2 Gb/in2, with a total recording capacity of 2.5 TB uncompressed.
Sony said it achieved this by “independently developing a soft magnetic underlayer with a smooth interface using sputter deposition,” a form of thin-film deposition in which electrostatic discharge is used to force argon ions to collide with the material. The materials generated from the collision become the thin layer deposited on the substrate. In this way, Sony created what it’s calling a “nano-grained” magnetic layer “with fine magnetic particles and uniform crystalline orientation.” The electronics giant said a coating of magnetic powder measuring tens of nanometers is considered mainstream for tape storage media.
Sony explained its methodology for creating this nano-grained layer measuring less than 5 micrometers: “Until now, when the sputter method was used to deposit a thin film of fine magnetic particles on a polymer film, roughness on the surface of the soft magnetic underlayer caused the orientation of the crystals in the underlayer above it to become non-uniform. This in turn caused non-uniform crystalline orientation and variations in the size of the magnetic particles (grain) in the nano-grained magnetic layer directly above the underlayer, and prevented increases in recording densities.
“By optimizing sputter conditions and independently developing a soft magnetic underlayer with a smooth interface, Sony has made it possible to minimize disparities in crystalline length and growth. This enabled Sony to create a nano-grained magnetic layer composed of fine magnetic particles with an average size of 7.7 nm.”
