Berlin 2018 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 17: Poster Session I
DS 17.39: Poster
Dienstag, 13. März 2018, 18:15–20:15, Poster B
Structural ordering of molybdenum disulfide studied via reactive molecular dynamics simulations — •Paolo Nicolini1, Rosario Capozza2, and Tomas Polcar1,3 — 1Czech Technical University in Prague, Prague, Czech Republic — 2Istituto Italiano di Tecnologia-IIT, Genova, Italy — 3nCATS, University of Southampton, Southampton, United Kingdom
Molybdenum disulfide, the most studied member of the transition metal dichalcogenides family, has been used as a solid lubricant for several decades, showing extremely low friction coefficients[1] and stability to high temperature. Its lubricating properties are ascribed to the weak van der Waals interactions between sulfur atoms in the crystalline layered structure. Moreover MoS2, even when prepared in the amorphous state or made of randomly oriented domains, can undergo shear induced structural transitions to the more ordered layered state affecting its tribological properties[2]. Exploiting a classical force field[3] able to treat explicitly formation and breaking of bonds, we investigate by molecular dynamics simulations, the shear induced structural changes and possible layer formation in the amorphous molybdenum disulfide. The ordering process is studied in details, with particular regard to the estimation of the thermodynamic properties that govern the process itself. A connection with crystallization theories is finally found, conferring a predictive power to the achieved results.
[1] J.M. Martin et al., Phys. Rev. B, 48, 10583(R) (1993). [2] J. Moser, F. Lévy, Thin Solid Films, 228, 257 (1993). [3] T. Liang et al., Phys. Rev. B, 79, 245110 (2009).