Effect of gamma irradiation on structural and optical properties of Cd₂SnO₄ thin films deposited by DC sputtering technique

The structural and the optical properties of DC sputtered Cd₂SnO₄ thin films before and after γ-irradiation (50–250 kGy) have been reported. The structural features of the as-deposited and γ-irradiation films are investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The optical constants of the as-deposited and γ-irradiation films have been obtained in the wavelength range 350–2000 nm by using spectrophotometric measurements at nearly normal incidence. The obtained optical constants were used to estimate the type of transition for the as-deposited and γ-irradiation thin films. In the normal dispersion region, the refractive index dispersion is discussed by using a single-oscillator model and Drude model. The single oscillator model is used to calculate the third-order nonlinear susceptibility, χ⁽³⁾. Also, the plasma frequency (ω_p) and free carrier concentration (N) are also calculated. - Highlights: • Effect of γ-irradiation on optical properties of Cd₂SnO₄ films has been reported. • X-ray diffraction and SEM have been used to identify the structure properties. • Using the fundamental absorption edge, the optical energy gap was estimated. • A single-oscillator model and Drude model were used to describe the refractive index