Surface and phase transformation characteristics of titanium hydride film under irradiation of pulsed ion beam

Abstract

Titanium hydride films irradiated by intense pulsed ion beam have been investigated by using scanning electronic microscopy, surface profilometer, X-ray diffraction and secondary ion mass spectroscopy in order to explore the mechanisms of interactions between intense pulsed ion beam and titanium hydride. Three sets of titanium hydride films are irradiated respectively for several times at energy density of 0.1J/cm2, 0.3J/cm2 and 0.5J/cm2. Surface morphologies start to reveal a feature of intense melting and network cracks only after energy density reaches close to 0.5J/cm2. Additionally, desorption of hydrogen from the film has been confirmed by X-ray diffraction, and a titanium dihydride (TiH2(x)) with a body centered tetragonal structure, seldom reported by researchers and formed under extreme conditions, has also been identified under this condition. Depth profile of hydrogen isotope with secondary ion mass spectroscopy seems to suggest that the bulk hydrogen isotope seems to serve as a reservoir for the drainage of top hydrogen, and its fast diffusion can quickly compensate for the exhaustion of top hydrogen isotope atoms.