Crystallinity dependent tribological behavior of molybdenum disulfide: Insights from experiments and atomistic simulations
Crystallinity dependent tribological behavior of molybdenum disulfide: Insights from experiments and atomistic simulations
The frictional and wear performance of molybdenum disulfide (MoS
2) is strongly governed by its crystallinity, yet this influence remains largely unexplored. In this study, we present the first integrated experimental and atomistic study that establishes how structural order governs the tribological performance of MoS
2. A wide spectrum of crystallinity, from amorphous to highly crystalline states, is investigated to evaluate its influence on the coefficient of friction (COF) and wear resistance. Experiments reveal a strong dependence of COF and wear on crystallinity, with crystalline MoS
2 achieving ultralow friction and enhanced wear resistance. In contrast, amorphous and polycrystalline films display significantly higher COF and pronounced tribo-polishing effect. Complementary reactive molecular dynamics simulations capture the same trend and uncover the underlying mechanics: crystalline MoS
2 maintains smooth sliding interfaces and enables frictional anisotropy through interlayer shear. However, sliding of disordered structures increases surface roughness, energy dissipation, and material removal. Furthermore, we examine the wear mechanisms under high normal loads, demonstrating that crystallinity enhances wear resistance by mitigating material deformation. The strong agreement between experiments and simulations confirms crystallinity as a dominant factor governing the tribological response of MoS
2. Our findings provide atomic-scale insights into the mechanisms of superlubricity in layered materials and offer a fundamental basis for designing advanced solid lubricants and wear-resistant coatings.
Crystallinity, Friction, Molecular dynamics, Molybdenum disulfide, Wear
Abhiram, B.R.
1a3d925b-5474-4546-8d81-5a15ea954889
Wang, Yue
9bdf0e18-c483-4a0b-afcc-10462fcf3fb2
Ponomarev, Ilia
bc5ab92f-ddb4-453c-8e98-3b4a04555172
Polcar, Tomas
c669b663-3ba9-4e7b-9f97-8ef5655ac6d2
23 January 2026
Abhiram, B.R.
1a3d925b-5474-4546-8d81-5a15ea954889
Wang, Yue
9bdf0e18-c483-4a0b-afcc-10462fcf3fb2
Ponomarev, Ilia
bc5ab92f-ddb4-453c-8e98-3b4a04555172
Polcar, Tomas
c669b663-3ba9-4e7b-9f97-8ef5655ac6d2
Abhiram, B.R., Wang, Yue, Ponomarev, Ilia and Polcar, Tomas
(2026)
Crystallinity dependent tribological behavior of molybdenum disulfide: Insights from experiments and atomistic simulations.
Tribology International, 218, [111660].
(doi:10.1016/j.triboint.2026.111660).
Abstract
The frictional and wear performance of molybdenum disulfide (MoS
2) is strongly governed by its crystallinity, yet this influence remains largely unexplored. In this study, we present the first integrated experimental and atomistic study that establishes how structural order governs the tribological performance of MoS
2. A wide spectrum of crystallinity, from amorphous to highly crystalline states, is investigated to evaluate its influence on the coefficient of friction (COF) and wear resistance. Experiments reveal a strong dependence of COF and wear on crystallinity, with crystalline MoS
2 achieving ultralow friction and enhanced wear resistance. In contrast, amorphous and polycrystalline films display significantly higher COF and pronounced tribo-polishing effect. Complementary reactive molecular dynamics simulations capture the same trend and uncover the underlying mechanics: crystalline MoS
2 maintains smooth sliding interfaces and enables frictional anisotropy through interlayer shear. However, sliding of disordered structures increases surface roughness, energy dissipation, and material removal. Furthermore, we examine the wear mechanisms under high normal loads, demonstrating that crystallinity enhances wear resistance by mitigating material deformation. The strong agreement between experiments and simulations confirms crystallinity as a dominant factor governing the tribological response of MoS
2. Our findings provide atomic-scale insights into the mechanisms of superlubricity in layered materials and offer a fundamental basis for designing advanced solid lubricants and wear-resistant coatings.
Text
VOR_1-s2.0-S0301679X26000022-main
- Version of Record
More information
Accepted/In Press date: 2 January 2026
e-pub ahead of print date: 22 January 2026
Published date: 23 January 2026
Keywords:
Crystallinity, Friction, Molecular dynamics, Molybdenum disulfide, Wear
Identifiers
Local EPrints ID: 511067
URI: http://eprints.soton.ac.uk/id/eprint/511067
ISSN: 0301-679X
PURE UUID: 595341c4-01fb-45a0-8e77-361d5d2eb268
Catalogue record
Date deposited: 30 Apr 2026 16:48
Last modified: 01 May 2026 01:49
Export record
Altmetrics
Contributors
Author:
B.R. Abhiram
Author:
Yue Wang
Author:
Ilia Ponomarev
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics
