Structural and morphological modifications in tungsten carbide thin films under low-energy Kr 2+ and He + ion irradiations

Abstract Tungsten carbide (WC) thin films, known for their exceptional thermal stability and mechanical strength, were systematically investigated for their response to ion irradiation using 200 keV Kr 2+ and 100 keV He + ions. The study aims to elucidate structural and surface modifications relevant to advanced applications in extreme radiation environments. Films deposited via DC magnetron sputtering were characterized before and after irradiation using glancing incidence x-ray diffraction (GIXRD), atomic force microscopy (AFM), and scanning electron microscopy (SEM). Kr 2+ irradiation, dominated by nuclear energy loss, led to pronounced grain refinement, lattice distortion, and surface nanostructuring, while He + irradiation caused only minimal changes due to lower nuclear energy loss value. Radiation-induced damage was further quantified through TRIM simulations and correlated with experimental parameters such as FWHM broadening and grain size evolution. The results demonstrate the strong fluence- and ion-mass-dependent behaviour of WC, highlighting its resilience against light ion exposure and providing critical insights into its potential use as a plasma-facing material in nuclear reactor.