Spectroscopic and microstructural characterization of 18 MeV He+ ions irradiated pure Al

Abstract

This study reports the spectroscopic and microstructural characterization of helium (He+) ions irradiated pure Aluminum (Al) (99.99%). The specimens of Al were irradiated by 18 MeV helium (He+) ions in the fluence range of 1 x 10(13) ions/cm(2) - 1 x 10(16) ions/cm(2) at 300 K under vacuum conditions using Cyclotron accelerator. The Field emission scanning electron microscope (FESEM) analysis reveals the generation and growth of cavities, micro size pits, voids and incoherent structures at various irradiation fluences, due to melting, re deposition and exfoliational sputtering of the irradiated surface. The X-ray diffractometer (XRD) results depicted significant variations in diffraction peaks intensities, peak shifting and broadening that became more pronounced with an increase of the irradiation fluence, whereas, anomalous behavior in crystallite size and lattice strain is observed after irradiation. These structural changes are related to the accumulation of irradiation induced stresses inside the lattice structure.