Study of 200 MeV Ag15+ ion induced amorphisation in nickel ferrite thin films

Thin films of nickel ferrite of thickness ∼100 and 150 nm were deposited by pulsed laser deposition. The films were irradiated with a 200 MeV Ag15+ beam of three fluences 1 × 1012, 2 × 1012 and 4 × 1012 ions/cm2. X-ray diffraction showed a decrease in the intensity of peaks indicating progressive amorphisation with increased irradiation fluence. Fourier transform infra-red and Raman spectra of pristine and irradiated films were also recorded which showed a degradation of the crystallinity of the samples after irradiation. The damage cross section of the infra-red bands was determined. It was found that the two bands at 557 and 614 cm−1 did not show similar behaviour with fluence.