Magnetic tape may seem to have long disappeared from daily life. But it is actually working harder than ever, making possible the long-term storage of a vast amount of data at the data centers of leading global IT companies, financial institutions, and other major corporations and organizations worldwide. The revitalization of tape emerged from 20 years of research at Fujifilm, resulting in an advanced new magnetic particle called barium ferrite (BaFe). Very quietly, BaFe tape has become a key component of today’s information society.
Some data, even if it is not accessed on a regular basis, is still mission-critical and absolutely cannot be lost. Data archiving requires a medium that can preserve a high volume of data over the long term with minimal risk of loss and with reasonable initial and running costs. BaFe magnetic tape fulfills all of these conditions better than any other medium. As an example of its effective use, in 2011, the email server of a renowned global IT company suffered a system failure, and a large volume of emails was temporarily inaccessible. Offline backups on magnetic tape saved the day, allowing the company to restore all of the missing emails quickly.
Yet the future of magnetic tape did not always look so bright. While the world’s data output continued to grow at an incredible rate, it was clear that, despite advances, the data storage capacity of standard metal particle tape would soon become a critical limiting factor. Fujifilm broke through this barrier by commercializing an entirely new magnetic material: BaFe.
The data capacity of magnetic tape is determined by the number of magnetic particles in its magnetic layer. A cartridge of BaFe tape can contain many more magnetic particles at a much higher density than a cartridge of conventional metal particle tape. In fact, today Fujifilm has developed prototype BaFe tape that could hold as much as 220 terabytes of uncompressed data if it were in a standard cartridge—world-record capacity that is 88 times that of conventional metal particle tape (Fujifilm research as of April 9, 2015).
BaFe particles are extremely small, while their shape makes possible very high-density orientation in the perpendicular direction. Moreover, their magnetic coercive force (the degree to which they can hold magnetization) is also large. The particles can be densely packed with little risk of magnetization reversal, enhancing data storage stability.
Developing a new high-capacity magnetic tape solution entails much more than developing the advanced magnetic material itself. Also required are the magnetic head to read and write the data in the magnetic layer as well as the drive to accommodate both the head and the tape. Together, these components make possible the archiving and restoring of data.
Although drive manufacturers had done their best to develop and supply the best possible hardware for metal tape applications, the industry knew they would eventually reach the physical limit to which metal particles could be made smaller, which in turn would limit the density of particles on the tape. BaFe simply had better characteristics, and Fujifilm believed BaFe tape would replace metal particle tape entirely.
In 1992, Fujifilm launched its research into BaFe as a next-generation storage tape medium. At the time, Fujifilm produced metal particle tape that was technologically one of the best on the market, but the competition was slowly but surely closing the gap: “At this rate, they’ll eventually overtake us. To launch BaFe as a new material, we need to demonstrate overwhelming superiority in recording density.” Such was the sense of urgency felt by Fujifilm’s engineers.
Despite high hopes, it proved difficult to achieve the necessary results. One significant barrier was the small size of BaFe particles. While this characteristic made it possible to pack the particles closely together, it also made them difficult to handle in other respects.
Fujifilm’s engineers had succeeded in coating tape in BaFe particles at ultra-high density and in an even, stable pattern at the nano scale. Even though they had created a magnetic storage tape prototype with world-record areal recording density, they were unable to write and read data from the tape with conventional tape heads and were thus unable to confirm the performance of the prototype.
The engineers concluded that conventional tape heads designed for metal tape were unable to read BaFe tape due to the small degree of magnetization exhibited by BaFe particles. At this point, they came up with the idea of developing their own tape head by altering a high-sensitivity magnetic head intended for use in hard disk drives—even though the architecture of the head for a hard disk drive is quite different from the head for a tape drive. They would then use this head to prototype an original evaluation system to confirm BaFe tape performance.
Altering the hardware to match the storage medium—this reversal of conventional wisdom led to a key breakthrough for the Fujifilm engineers, who were used to seeing things from the perspective of a tape manufacturer. It was decided that this would be the final experiment and last chance to make BaFe tape a reality. No results would mean no more development project.
The idea worked. Using the high-sensitive head they had specially fabricated, the engineers demonstrated that their BaFe tape offered double the storage capacity of the most advanced metal particle tape of the time.
Before BaFe tape could be commercialized, however, much work lay ahead. One large task was working with IBM to assess the potential of BaFe tape. Since IBM's equipment for assessing magnetic tape was designed for metal tape, it could not accurately read the signal from Fujifilm’s BaFe tape. Moreover, IBM continued to succeed with metal tape and thus were not easy to invest in the development of new drive technologies for different type of magnetic tape. "It looks like we’ll have to make some basic research more about evaluation by ourselves," was the conclusion of the Fujifilm engineers. Undaunted, they plunged into the work of developing an evaluation system with a high-sensitivity head.
Needless to say, this next stage was anything but easy. Basic research into tape heads and drives was well outside the core expertise of a materials manufacturer like Fujifilm. Fujifilm's engineers formed a special team within the company to research a device to evaluate the true performance of BaFe tape. After expending much effort, they succeeded in demonstrating the high recording density of Fujifilm’s BaFe tape. Five years after the first discussions with Fujifilm about BaFe, IBM was able to perform experiments on the new medium. IBM soon confirmed the outstanding performance of BaFe tape and agreed to participate in joint research and development of the technology with Fujifilm.
A Fujifilm engineer comments: “We were total beginners when it came to tape drives. That meant that we didn’t have any preconceptions about the technology when we started. Since we had never developed metal particle tape drives, previous performance results were no psychological barrier. We took the challenge head-on.”
In 2011, Fujifilm launched the world’s first commercial BaFe data storage cartridge. Since then, BaFe tape’s data storage capacity has continued to grow at a rapid pace, and all drive manufacturers currently offer hardware for BaFe tape applications.
Cloud services and Big Data analysis now drive many aspects of our everyday lives, and the Internet of Things (IoT) is already becoming a familiar presence. The volume of data generated and transmitted is only accelerating, and the frequency with which we access data and its overall value to us is also increasing. Surprisingly, a technology associated with the 20th century, magnetic tape, has an important new role to play in this future. And Fujifilm's innovation in advanced materials made it happen.