The Key Role of Tin (Sn) in Microstructure and Mechanical Properties of TiSnC (MAX) Thin Nanocrystalline Films and Powdered Polycrystalline Samples.

Layered ternary TiSnC carbides have attracted significant attention because of their advantage as a M2AX phase to bridge the gap between properties of metals and ceramics. In this study, TiSnC materials were synthesized by two different methods-an unconventional low-energy ion facility (LEIF) based on Ar ion beam sputtering of the Ti, Sn, and C targets and sintering of a compressed mixture consisting of Ti, Sn, and C elemental powders up to 1250 °C. The TiSnC nanocrystalline thin films obtained by LEIF were irradiated by Ar ions with an energy of 30 keV to the fluence of 1.10 cm in order to examine their irradiation-induced resistivity. Quantitative structural analysis obtained by Cs-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) confirmed transition from ternary TiSnC to binary TiC carbide due to irradiation-induced β-Sn surface segregation. The nanoindentation of TiSnC thin nanocrystalline films and TiSnC polycrystalline powders shows that irradiation did not affect significantly their mechanical properties when concerning their hardness (H) and Young's modulus (E). We highlighted the importance of the HAADF-STEM techniques to track atomic pathways clarifying the behavior of Sn atoms at the proximity of irradiation-induced nanoscale defects in TiSnC thin films.