Magnetic Tape Storage Takes Big Step Forward

How do you store your data? On the hard drive of your computer? On a disk, a flash drive, or the cloud?

Your data on the cloud must be stored somewhere, right? In fact, your information could well be stored on magnetic tape, the most economical data storage option. Tape allows long-term storage of 15-30 years of data archives, and in our information-overloaded life, the need for data storage is expanding.

Now, this form of storage has taken a big step forward with the development of a magnetic tape technology that increases areal recording density of current mainstream coated magnetic tape storage media by approximately 74 times.

Computer storage cassettes from the early days of home computing.
When you think of computer tape storage, does you mind go back to these cassettes of yore?

History of Tape Storage

What is magnetic tape and how is it used for data storage?

Magnetic tape was initially used for audio recording in Germany before the Second World War. The original tape used particles of ferric oxide (rust), which is ferromagnetic, i.e., it shows spontaneous magnetization. During data recording, the particles on the tape are magnetized and keep their polarity during storage.

The development of magnetic data storage started in the 1950s with the first data recorded on a strip of nickel-plated bronze. Modern magnetic tape for data storage uses a polyester film coated with a layer of chromium oxide or iron-cobalt oxide particles, and, more recently, barium ferrite particles. The size of iron-cobalt alloy particles is in the range of 40-100nm, while barium ferrite particles are around 20 nm, determined by electron microscopy. Smaller particles result in “better performance, better head-wear properties and better archival properties,” according to IBM, where the magnetic tape is routinely tested in warm/wet, hot/wet, hot/dry, cold/dry and cold/wet environments to mimic real-life conditions (PDF). Reducing the size and achieving uniform orientation of the particles is important for a higher signal-to-noise ratio and a lower bit-error rate.

New Development

According to a Sony news release, a radical increase in storage density has been achieved by significantly decreasing the size of the magnetic particles:

Sony Corporation today announced that by independently developing a soft magnetic underlayer with a smooth interface using sputter deposition, it has succeeded in creating a nano-grained magnetic layer with fine magnetic particles and uniform crystalline orientation. This enabled Sony to successfully develop magnetic tape technology that achieves the world’s highest areal recording density for tape storage media of 148 gigabits per square inch. This areal recording density is equivalent to approximately 74 times the capacity of current mainstream coated magnetic tape storage media, and makes it possible to record more than 185 TB (terabytes) of data per data cartridge.

The previous record was set by IBM 4 years ago at 29.5 gigabits per square inch, as described in the video:

IBM assisted Sony with measuring and accessing the recording density of their new technology, which is to be presented at the INTERMAG Europe 2014 international magnetics conference this week in Dresden, Germany. The new technology uses sputter deposition in a vacuum and results in extremely fine (7.7 nm on the average) crystal particles with uniform orientation on a thin, 5 micron polymer film. The key to the uniform crystal orientation is the soft magnetic underlayer with a smooth surface, because it is the roughness of the layer under the crystals that determines the crystal orientation.

Why is data storage so important? Think of rapid data recovery in databases and servers after natural disasters and  information security. And as cloud service becomes more and more a part of our lives, the need for data storage will continue to expand.

Image by ProhibitOnions.
Source: “Barium Ferrite: The Storage Media of the Future Is Here Today,” ibm.com.
Source: “Sony develops magnetic tape technology with the world’s highest areal recording density of 148 Gb/square inch,” news release, sony.net, April 30, 2014.
Source: IEEE International Magnetics Conference, intermag2014.ifw-dresden.de.
Video: “Made in IBM Labs: IBM Research Sets New Record in Magnetic,” by IBM Research – Zurich (Rüschlikon).