Heat-assisted magnetic recording

The English term heat -assisted magnetic recording ( HAMR, dt heat -assisted magnetic recording ) refers to a process for storing information in magnetic materials, which produce even greater data densities in hard disk drives. Thus, should in future be possible disks with volumes in the mid-double -digit terabyte range. Seagate demonstrated the summer of 2002 the first laboratory technology with HAMR. In 2013, first production models were announced.

The process

With HAMR is the domain in which data is to be written first heated locally by a laser above the Curie temperature in order to maintain the necessary for a write magnetic field as small as possible and to enable writing despite weak superparamagnetic effect. With increasing reduction of the magnetic dots to store a bit, sometime occurs the superparamagnetic effect, wherein the magnetic force is subject to the heat, and the ferromagnetic magnetization becomes unstable. Available thermally stable magnetic materials require higher coercive force for permanent magnetization comparable large magnet points. In conventional perpendicular recording therefore always higher magnetic field strengths are necessary, with the limits of realizable field strengths in 2013 are considered to be largely exhausted and impede further miniaturization. With the help of heating, this limitation is bypassed. Since when heated but evaporates the protective lubricant of the hard drive, the hard drive manufacturer Seagate wants to store supplies in nanometer-thin carbon tubes from which lubricant can be released to the plate surface, if necessary.

Expectations

It is speculated that memory capacity can be achieved by means of this technology. In 2007, Seagate expected that in 2010 capacity can be achieved of 37.5 terabytes. In October 2013 Seagate reduced this planning up to 20 terabytes in 2.5 -inch hard drives by 2020. That would be 5 times as much as the time of the announcement largest hard drive with about 4 terabytes. However, it is also reported that through this technology could increase the number of head crashes and thus the quality of the hard drive would suffer.