Issue 39, 2017

Superior wear resistance and low friction in hybrid ultrathin silicon nitride/carbon films: synergy of the interfacial chemistry and carbon microstructure

Abstract

Amorphous carbon-based films are commonly investigated as protective nanocoatings in macro- to nano-scale devices due to their exceptional tribological and mechanical properties. However, with further device miniaturization where even thinner coatings are required, the wear durability of the nanocoating rapidly degrades at the expense of lower thickness. Here we discover that for sub-10 nm coating thicknesses, a hybrid bi-layer film structure, comprising a high sp3-bonded amorphous carbon top layer and a silicon nitride (SiNx) bottom layer, consistently outperforms its single-layer amorphous carbon counterpart in terms of wear durability on a commercial tape drive head, while exhibiting low, stable friction and excellent wear resistance on a flat ceramic substrate. The superior performance of the hybrid film is attributed to the constructive synergy of the sp3-rich carbon microstructure and an enhanced interfacial chemistry arising from additional interfacial bonding. Moreover, a high energy C+ ion treatment step, introduced either directly to the substrate or to the SiNx layer before carbon deposition, also aids in increasing atomic mixing that contributes to further improvement in the wear resistance. This study highlights the importance of both the carbon microstructure and interfacial chemistry in the design of wear-durable nanocoatings at few-nanometer thicknesses, particularly for aggressive wear conditions.

Graphical abstract: Superior wear resistance and low friction in hybrid ultrathin silicon nitride/carbon films: synergy of the interfacial chemistry and carbon microstructure

Supplementary files

Article information

Article type
Paper
Submitted
25 May 2017
Accepted
30 Aug 2017
First published
31 Aug 2017

Nanoscale, 2017,9, 14937-14951

Superior wear resistance and low friction in hybrid ultrathin silicon nitride/carbon films: synergy of the interfacial chemistry and carbon microstructure

R. J. Yeo, N. Dwivedi, L. Zhang, Z. Zhang, C. Y. H. Lim, S. Tripathy and C. S. Bhatia, Nanoscale, 2017, 9, 14937 DOI: 10.1039/C7NR03737F

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements