Gamma irradiation effects on structural and optical properties of amorphous and crystalline Nb2O5 thin films

Abstract

The structural and optical properties of RF sputtered Nb2O5 thin films are studied before and after gamma irradiation. The films are subjected to structural and surface morphological analyses by using X-ray (XRD) and field emission scanning electron microscope techniques. In the wavelength range of 300–2000 nm, the optical parameters for amorphous and crystalline Nb2O5 thin films are estimated at differently exposed γ-irradiation doses (0, 50, 100 and 200 kGy). The optical constants, such as optical energy band gap, absorption coefficient, refractive index and oscillators parameters of amorphous and crystalline Nb2O5 thin films are calculated. The optical band gaps of γ-irradiated amorphous and crystalline Nb2O5 thin films are determined. In the non-absorbing region, the real part of the refractive index of amorphous and crystalline Nb2O5 thin films slightly increases with the increase in the exposed γ-irradiation dose.