Materials for Magnetic Data Storage: The Ongoing Quest for Superior Magnetic Materials

Abstract

From its inception until today, and for the foreseeable future, magnetic data storage on disks and tape has provided constantly increased storage density. This has required not only constant innovation, but also major breakthroughs in magnetic materials, both for the media and the read head. Today's disk and tape drives take advantage of novel nanoengineered composite magnetic materials and quantum mechanical processes. In this issue of MRS Bulletin, we present a number of review articles by some of the leaders in this rapidly moving field that highlight the key materials science accomplishments that have enabled the tremendous progress in hard disk drive and magnetic tape technologies. Individual articles describe the materials involved in stateof-the-art magnetic recording, advanced media for perpendicular magnetic recording, the materials challenges of achieving high performance in flexible media such as magnetic tape, the materials issues of read heads, and future avenues for magnetic storage beyond magnetic recording, such as nanowires and spintronics.

Experimental evidence for the formation of CoFe2C phase with colossal magnetocrystalline-anisotropy

“…The primary source of the enhanced anisotropy is the controlled mixing between the Fe or Co d-states and the C p-states. 15 From all the obtained results, CoFe 2 C nanomagnets have the superior magnetic properties and can be a good candidate for data storage applications. 16 Moreover, the estimated thermal stability constant (TSc; ratio between magnetic anisotropy and thermal energy, depending on the magnetic size and the phase transition temperature of 5 nm and 790 K, respectively) was 73, which is higher than that of the FePt materials (TSc ¼ 60) 16 currently used for data storage devices.…”

Perspective: Ultrafast magnetism and THz spintronics

“…74 Analogous to Moore's law, one sees the impressive developments comparing the bit density of 1995 with current memories: there has been a decrease in price by a factor of 100 000. In 1995, the price/GBit in hard disk storage devices reached parity with the price of information storage by printing it on paper, 75 which set the stage for our information technology and cloud computing today. Strong developments were made in the hard disc industry bringing us TBit/cm memories with bit sizes of $12 Â 22 nm to a few thousands atoms only over the last years.…”

Metal Evaporated Media

“…2.1. Such evolution has been supported by constant innovations and technical breakthroughs (Bandic and Victora, 2008;Coufal et al, 2006). Hard disk drives now record data at more than 500,000,000,000 bits/in.…”