The latest Magnetism and Magnetic Materials (MMM) Conference, organized by the IEEE Magnetics Society and the American Physical Society in Las Vegas 2015, was an oportunity for several speakers to discuss advances in hard disk drive technology and other spin-based non-volatile memory devices. Hard disk drives are a very popular digital storage devices primarly because of their low cost. 2015 model hard disk drives are reported to have up to 10 TB of storage capacity. The development of 8 and now 10 TB drives involves the introduction of differing technologies such as shingled magnetic recording (SMR) or helium-filled hard disk drives.
100TB hard disk drive is expected to arrive by 2025
The SMR technology will not likely add much more to areal density growth. In addition, putting helium in a hard drive will only allow a limited addition of disks to a drive. Therefore higher storage capacity will require new digital storage technology. According to the Advanced Storage Technology Consortium’s (ASTC) roadmap, technology like Heat Assisted Magnetic Recording (HAMR) could be introduced by 2017, thus increasing the average annual areal density growth rate from the current 15% to in impressive 30%. The roadmap also shows another new innovation, bit pattern media (magnetic media broken into small regions on the disk surface) which could be realized by 2021 and combined with SMR or an extension to SMR called Two Dimensional Magnetic Recording (TDMR). These new technologies are expected to compliment HAMR, resulting in up to 10 Terra-bit per square inch (Tbpsi) areal densities by 2025. Today’s hard disk drives have an areal density up to 0.86 Tbpsi. To put this in perspective, a 3.5-inch hard disk drive built in 2025 may be capable of 100 TB of storage capacity.
Solid State Drives
The Magnetism and Magnetic Materials conference also featured several sessions focused on the latest research on magnetic spin-based storage and processing technologies. One of which focused upon electron properties responsible for creating current in present day electronics, in particular the property called spin, associated with a magnetic field. Read sensors in hard disk drives have used spin-based technology as sensitive magnetic field detectors for more than 15 years. This technology is now being advanced for use in solid-state storage technology. These spin-based magnetic random access memory (MRAM) technologies are most promising for replacing the semiconductor-based SRAM and DRAM which now serve as the expensive main memory in most computers that use non-volatile memory technology. MRAM devices retain their memory when power is turned off while SRAM and DRAM require electrical energy to retain memory. MRAM can also be used as cache memory and is desirable for cache memory in secondary storage devices.
Final Thoughts
Magnetic technology continues to progresses and meet the needs of future mass-storage markets despite the advances of flash-based technologies. Don’t count out magnetic technology just yet.
