Ultrathin Carbon with Interspersed Graphene/Fullerene-like Nanostructures: A Durable Protective Overcoat for High Density Magnetic Storage.
Sci Rep 2015;
5:11607. [PMID:
26109208 PMCID:
PMC4479824 DOI:
10.1038/srep11607]
[Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 05/11/2015] [Indexed: 12/02/2022] Open
Abstract
One of the key issues for future hard disk drive technology is to design and develop
ultrathin (<2 nm) overcoats with excellent wear- and corrosion
protection and high thermal stability. Forming carbon overcoats (COCs) having
interspersed nanostructures by the filtered cathodic vacuum arc (FCVA) process can
be an effective approach to achieve the desired target. In this work, by employing a
novel bi-level surface modification approach using FCVA, the formation of a high
sp3 bonded ultrathin (~1.7 nm) amorphous
carbon overcoat with interspersed graphene/fullerene-like nanostructures, grown on
magnetic hard disk media, is reported. The in-depth spectroscopic and microscopic
analyses by high resolution transmission electron microscopy, scanning tunneling
microscopy, time-of-flight secondary ion mass spectrometry, and Raman spectroscopy
support the observed findings. Despite a reduction of ~37 % in COC
thickness, the FCVA-processed thinner COC (~1.7 nm) shows
promising functional performance in terms of lower coefficient of friction
(~0.25), higher wear resistance, lower surface energy, excellent
hydrophobicity and similar/better oxidation corrosion resistance than current
commercial COCs of thickness ~2.7 nm. The surface and
tribological properties of FCVA-deposited COC was further improved after deposition
of lubricant layer.
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