A detailed investigation of surface modification in metallic glasses subjected to 130 MeV 28Si ion irradiation

Abstract

Surface modification induced in four metallic glasses by4.64 MeV/u 28Si ion irradiation has been investigated in detail using optical microscopy, SEM and STM. Results obtained in two separate runs have been presented here. The effects of ion fluence (/) and tilt angle (h) on surface modification have been studied both qualitativelyand quantitatively. It has been found that for Se values smaller than that for track formation, swift heavyion irradiation leads to smoothing of the irradiated surfaces. The smoothing is evident from decreasing mean roughness Rq and reduction in height of the hills and filling up of the valleys in the SEM and STM pictures. The observations have been explained on the basis of the theoryof shear flow within the framework of the viscoelastic model.