Irradiation induced modification in transport properties of LaNiO3 thin films: An x-ray absorption study

Highly c-axis oriented LaNiO3 thin films are grown on LaAlO3 (001) single crystal substrates using rf-magnetron sputtering. Swift heavy ion irradiation induced variations in structural and electrical transport properties of deposited films are studied. Pristine film shows unusual insulating character while the irradiated film exhibits metallic behaviour. X-ray diffraction study indicates that irradiation improves the crystalline character of films while retaining the oriented single phase growth. Electronic structure measurements performed using x-ray absorption spectroscopy at O K, La M-5.4, and Ni L-3,L-2-edges reveal that Ni-O hybridization-controlled localization of charge carriers is responsible for the observed transport behaviour. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4752005]