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Researchers Propose Graphene Overcoats for HAMR HDD Platters

Seagate
(Image credit: Seagate)

Heat-assisted magnetic recording (HAMR) technology promises to enable hard drives with a 100TB capacity in about a decade from now. But HAMR requires all-new record heads with a transducer that heats up platters as well as new types of media. Researchers at the Cambridge Graphene Centre believe that in addition to new heads and platters makers of HDDs will also have to use new graphene-based overcoats to protect platters from damage and corrosion. 

Contemporary HDDs that rely on perpendicular magnetic recording (PMR) technology use aluminum or glass platters with CoCrPt–SiO2 nanogranular magnetic films as well as Carbon-based overcoats (COCs). Hard drives based on HAMR use glass platters with magnetic films featuring high magnetocrystalline anisotropy to ensure very small grains, such as an iron platinum alloy (e.g., L10–FePt). Researchers at the Cambridge Graphene Centre believe that traditional COCs are not optimal for HAMR drives since they will have to handle extreme temperatures for long durations.

In a bid to understand viability of graphene-based coatings for hard drive platters, researchers replaced commercial COCs with one to four layers of graphene, and tested resistance, wear, corrosion, thermal stability, and lubricant compatibility. According to the scientists, graphene enables a two-fold decrease in resistance, lowers corrosion by 2.5 times, and reduces wear when compared to COCs.  

"This work showcases the excellent mechanical, corrosion and wear resistance properties of graphene for ultra-high storage density magnetic media," said Andrea C. Ferrari, Director of the Cambridge Graphene Centre. "Considering that in 2020, around 1 billion terabytes of fresh HDD storage was produced, these results indicate a route for mass application of graphene in cutting-edge technologies." 

Seagate, the only company that ships HAMR HDDs commercially, does not use graphene for its 20TB drives, but as technology matures, it is possible to expect it to switch to new types of overcoats.  

A detailed report about the experiment is published at Nature Communications

  • watzupken
    There are certainly merits to use graphene here, but in doing so, it will drive prices up. Graphene is not cheap to begin with.
    Reply
  • sepuko
    watzupken said:
    There are certainly merits to use graphene here, but in doing so, it will drive prices up. Graphene is not cheap to begin with.
    In 10 years it might be a lot cheaper, plus as far as I understand the coating does not require one uninterrupted lattice(which is very hard to achieve now), the coating could probably work with bits of graphene(which is comparatively cheap now).
    Reply
  • gfg
    "drives with a 100TB capacity in about a decade from now"...
    In 10 years 100TB will be obsolet, now we have 20 TB.
    Reply
  • tommo1982
    ... they will have to handle extreme temperatures for long durations.

    Heat dissipation might be a problem. I didn't see it mentioned anywhere. I wonder how they will deal with cooling.
    Reply
  • hannibal
    $2000 chiller ;)
    Reply
  • InvalidError
    watzupken said:
    There are certainly merits to use graphene here, but in doing so, it will drive prices up. Graphene is not cheap to begin with.
    The cost of graphene depends on the size, uniformity and purity of flakes you need.

    Graphene is the main component in pencil leads (you write/draw when the lead sheds graphene flecks that wedge themselves between paper fibers) and one pencil probably contains more graphene than necessary to manufacture one HDD.

    Unless HDDs have strict Goldilocks graphene requirements, graphene shouldn't be a major cost driver. The process to give platters a uniform coating and get it to stick could be a different story.
    Reply
  • jakjawagon
    COCs are not optimal for HAMR drives

    Don't HAMR your COC. Got it.
    Reply
  • kawmic
    Why keep on developing hdd's?? SSD is here to stay! HDD is filled with <Mod Edit> moving parts. DROP IT!!
    Reply
  • USAFRet
    kawmic said:
    Why keep on developing hdd's?? SSD is here to stay! HDD is filled with <Mod Edit> moving parts. DROP IT!!
    All my house systems are SSD only.

    However...the 65TB in or attached to my NAS...I could either replace that with all solid state, or buy another car.

    HDDs have their place.
    Reply