title: Tailoring Nanoscale Friction in MX2 Transition Metal Dichalcogenides.
abstract: Lattice dynamics of MX2 transition metal dichalcogenides (M = Mo, W; X = S, Se, Te) have been studied with density functional theory techniques to control the macroscopic tribological behavior. Long-range van der Waals forces have been modeled with Grimme correction to capture the interlayer interactions. A new lattice dynamic metric, named cophonicity, is proposed and used in combination with electronic and geometric descriptors to relate the stability of the lattice distortions with the electro-structural features of the system. The cophonicity analysis shows that the distortion modes relevant to the microscopic friction can be controlled by tuning the relative M/X atomic contributions to the phonon density of states. Guidelines on how to engineer macroscopic friction at nanoscale are formulated, and finally applied to design a new Ti-doped MoS2 phase with enhanced tribologic properties.
authors.affiliation: †Department of Control Engineering, Czech Technical University in Prague, Technicka 2, 16627 Prague 6, Czech Republic.
authors.forename: Antonio
authors.initials: A
authors.lastname: Cammarata
authors.affiliation: †Department of Control Engineering, Czech Technical University in Prague, Technicka 2, 16627 Prague 6, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Polcar