Effect of annealing and swift heavy ions irradiation on vanadium oxide thin films

Abstract

In this work, thin films (∼200 nm) of vanadium oxide were deposited on Si (100) substrate by e-beam evaporation method with low-cost V2O5 powder. Some of the as-deposited samples were annealed in the argon atmosphere at 500°C for 1 h and cooled at a natural rate in the argon atmosphere. The as-deposited samples were also irradiated with 100 MeV Ag ions beam at different fluences. Grazing incidence X-ray diffraction (GIXRD) and Raman spectroscopy revealed that as-deposited films were composed of the V6O13 phase (mixed valance state). This V6O13 phase was transformed into polycrystalline V2O5 phase after post-annealing. Raman spectra of irradiated films had a new peak of the V6O13 phase, and no change was observed at higher fluence, and in the FTIR spectra, bands shifted toward lower wavenumber side at higher fluence. This band shifting toward the lower wavenumber side may be due to the weakening of vanadium oxygen bonds, which create oxygen vacancies in the film. The creation of defects in films was due to the pressure applied by the molten zone, which is formed by the passage of SHIs in the material.