The new graphene-based material, created by an international team of scientists, will increase the capacity of hard drives by an order of magnitude compared to today’s models. Multilayer graphene has proven to be much more efficient than the carbon compounds used today to cover discs in storage devices.
Graphene made it to hard drives
An international team of researchers from Graphene Flagship and a number of scientific institutions in the UK, Switzerland, India, Singapore and the United States presented the technology of using graphene in the production of components for ultra-high density magnetic disk drives.
According to scientists who published the results of the study in the article “Graphene overcoats for ultra-high storage density magnetic media” in the scientific publication Nature, the introduction of the new material will increase the recording density of magnetic disks from the current units of terabit to square inch to ten terabits in the same area.
For these purposes, the article proposes to use multilayer graphene as a replacement for coatings based on carbon compounds, which are used in modern storage drives to protect magnetic plates from corrosion and mechanical damage, and at the same time occupy most of the gap between magnetic disks and magnetic heads.
“This work demonstrates the superior mechanical, corrosion and wear-resistant properties of graphene for ultra-high density magnetic media,” said Andrea C. Ferrari, director of science and technology for Graphene Flagship. “With nearly 1 billion terabytes of new hard drives produced in 2020, these results demonstrate the potential of graphene for the mass market.”
Despite the significant recent increase in the popularity of solid-state drives, especially popular in mobile devices and mission-critical enterprise storage systems, hard drives are still popular for storing data in personal systems and data centers – mainly due to their lower cost.
Data is written in hard drives onto platters using magnetic heads that move rapidly over spinning platters. The smaller the gap between the platter and the head, the greater the storage density the drive can provide. The switch to carbon-based coatings reduced their thickness from 12.5 nm in the 1990s to about 3 nm, and brought the recording density to about terabyte per square meter. inch.
To further increase storage density and achieve a level of about 10 terabytes per sq. inch, it is necessary to use coatings based on carbon compounds with a thickness of less than one nanometer, however, modern coatings of this class lose their useful properties at a thickness of less than 2 nm.
Researchers at Graphene Flagship have developed a technology for using graphene plate coatings. In their paper, they described coatings ranging from one to four levels of graphene that were tested for friction, wear, corrosion, thermal stability, surface smoothness, and lubricant compatibility.
Research has confirmed that graphene can cut friction in half and provide better protection against corrosion and wear than modern carbon coatings. The use of one layer of graphene made it possible to reduce corrosion by 2.5 times. The multilayer graphene coating showed a decrease in the wear rate by three orders of magnitude.
Combination with other promising technologies
The deposition of a one to four-layer graphene coating was carried out in experiments by chemical vapor deposition (CVD) and transferring a hard disk made of a copper alloy to the plates. A similar technology is used in the modern technical process for the production of hard drives.
Developers at Graphene Flagship have also explored the technology of transferring graphene onto discs with iron-platinum-plated wafers (FePt) as a magnetic recording layer to test a promising Heat-Assisted Magnetic Recording (HAMR) technology that increases data storage density by heating the recording layer to high temperatures.
Experiments have confirmed that protective graphene coatings can withstand the high temperatures of HAMR technology without degradation. According to the researchers, graphene-based coatings, combined with other innovative technologies such as HAMR and Bit Patterned Magnetic Recording (BPM), can increase the storage density of up to 10 terabytes per square meter. inch or more.
In addition to researchers from Graphene Flagship, scientists from the University of Cambridge, Great Britain, the Federal Polytechnic School of Lausanne (EPFL), Switzerland, the Swiss Federal Laboratories of Materials Science and Technology Empa, Switzerland, the University of Exeter, Great Britain, the CSIR-Advanced Materials Institute took part in the development of the technology and the publication of the article. and Processes Research Institute, India, National University of Singapore (NUS), Agency for Science, Technology and Research (A * STAR), Singapore, University of Illinois and Argonne National Laboratory, USA.
Earlier, Live News Planet told about the forecast of analysts from IDC, according to which, by 2024, up to 54% of all information will be stored on magnetic disks (the figure for 2018 was 65%). Another IDC report, Global StorageSphere, which predicts growth in storage capacity, notes that by the end of 2020, installed storage capacity worldwide will grow by 16.6% to 6.8 zetabytes, and in 2019-2024. the average annual growth of the volume will be about 17.8%.