Change of electrical properties of (K_0.5Na_0.5) (Mn_0.005Nb_0.995)O₃ thin films induced by gamma-ray irradiation

We investigated the effects of gamma-ray (γ) irradiation on the electrical properties of (K_0.5Na_0.5) (Mn_0.005Nb_0.995)O₃ (KNMN) thin films. The KNMN thin films were prepared on Pt/Ti/SiO₂/Si substrate using a chemical solution deposition method through a spin-coating process and were subject to γ radiation at various total doses from 0 to 3000 kGy. The structural properties as well as the ferroelectric and dielectric properties of the prepared films were examined before and after γ irradiation. We found that their crystalline quality did not vary significantly with an increase in the total dose. It was also observed that the remnant polarization value of the films decreased by ∼10%, but the films maintained ferroelectricity even after irradiation up to 3000 kGy. In addition, the dielectric constant of the films decreased with the total dose. The observed variation of the electrical properties on the total dose might be mainly associated with the mobile defects in Mn-doped KNN thin films such oxygen vacancy and the stored energy gained from gamma-rays.