Morphological study of borosilicate glass surface irradiated by heavy ions

Borosilicate glass is a candidate material for radiation waste formation and other optical applications in various fields. To understand the radiation effect of borosilicate glass, heavy ion (Arq +, Krq + and Xeq +) irradiations were used to simulate the alpha and recoiled nuclei irradiations in this study. The surface morphology of glass has been compared to ion irradiation doses and ion energies. The surface topography evolution of irradiated samples is characterized by optical microscopy, atomic force microscopy (AFM), transmission electron microscopy (TEM) and secondary ion mass spectrometry (SIMS). Micro-bumps are observed on the sample surface after irradiation with 5 MeV Xeq + over 5 × 1013 ions·cm− 2. The size and density of the bumps increases with increasing irradiation dose. At a low dose, bumps are on the nanometer (nm) scale and rather rare. While the dose is higher than 9 × 1015 ions·cm− 2, the size of bumps is on the scale of a few microns, and the density is saturated. However, the height of the bumps increases from a few nm to over 150 nm with further irradiation. The distribution of micro-bumps is nearly homogeneous. The bumps are condensed and swell up, and there is no crystallized structure according to the TEM diffraction pattern. Element migration and concentrations are observed with SIMS imaging. The arrayed micro-bumps are a new finding, and they might be used to change the surface properties. Bump formation is caused by phase separation, and volume swelling is induced by ion irradiation.