Amorphization and disorder of PrFeO3 thin films after heavy ion irradiation

We present structural, morphological, optical absorption and Raman study of 200 MeV Ag(15+) ion irradiated PrFeO(3) thin film of around 200 nm thickness deposited on LaAlO(3) [001] substrate by using the pulsed laser deposition technique. X-ray diffraction studies shows that it has an orthorhombic structure with Pbnm space group and is grown with (001)-orientation. The substrate-induced strain is found to be small and is found to increase for ion fluence. UV-visible spectra shows enhancement of optical band gap with ion fluence. At room temperature Raman spectra, the different Raman modes observed are classified according to the orthorhombic structure. All the observed modes show variation in Raman shift with rise in ion fluences. The line width and position variations with fluence for observed modes are correlated with octahedral distortion of FeO(6), Fe-O bond length and as well as O-Fe-O bond angle. Surface morphology and grain size also get affected with ion fluences. Many possibilities have been explored to explain the observed results.