Structural and mechanical properties changes induced in nanocrystalline ZrC thin films by Ar ion irradiation

Abstract Thin ZrC films ( 11  cm 2  s −1 with fluences ranging from 1 × 10 14 at/cm 2 to 2 × 10 15  at/cm 2 . Glancing incidence X-ray diffraction, X-ray reflectivity, transmission electron microscopy and nanoindentation investigations were used to study the structural modifications in the films' density, composition and mechanical properties induced by irradiation. After irradiation, the lattice parameter and crystallite size slightly increased, while the films' density decreased. Significant decreases in nanohardness and Young modulus values were also measured after irradiation at 1 × 10 14  at/cm 2 and 1 × 10 15  at/cm 2 fluences. No further major decreases were observed for a fluence of 2 × 10 15  at/cm 2 . Scanning transmission electron microscopy and energy dispersive X-ray analysis showed a decrease in the Zr/C values in the irradiated film from surface towards the Si substrate.