Influence of argon ion beam irradiation on the structure, optical, and dielectric properties of the flexible PEO/CeO2 nanocomposite film
摘要
In the present work, low energy argon ion beams were utilized to change the structure, optical, and dielectric properties of the flexible polyethylene oxide/cerium oxide (PEO/CeO2) nanocomposite film, which was fabricated using the solution-casting method. The XRD analysis confirmed the change in film structure upon irradiation through the decrease in peaks intensity and significant broadening, reflecting a reduction in crystallinity. Moreover, the FTIR also revealed the alteration in structure of the treated films due to the reduction in peaks intensity and peaks shift. The SEM images confirmed the progressive increase in roughness and porosity of the treated films. Meanwhile, the interaction of energetic Ar⁺ ions with PEO/CeO2 nanocomposite films was simulated using SRIM and TRIM codes. These changes in structure led to improving the optical and dielectric properties of the treated films compared to pristine film. In which, the optical band gap decreased from 4.70 eV of the untreated film to 4.59, 4.49, and 4.24 eV of the treated PEO/CeO2 films at fluence 2 × 1016, 4 × 1016, and 6 × 1016 ions/cm2, respectively. This reduction in values of band gap were accompanied by an increase in Urbach energy from 1.88 eV to 2.00, 2.14, and 2.31 eV, respectively. In addition, at 0.1 Hz, a great increase in dielectric constant (ε′) and dielectric loss (ε″) values were noticed after irradiation, which led to improving the discharged energy density (U) of the untreated film from 0.054 to 0.16 J/m3 of the treated film by 6 × 1016 ions/cm2, respectively. At 100 Hz, the Ac conductivity of the pristine film also increased from 7.62 × 10–7 S/m to 1.84 × 10–6 S/m upon irradiation using 6 × 1016 ions/m2. In opposite, the electric modulus and complex impedance behaviors decreased with an increase in fluence of ion beam irradiation. Besides, a respectively reduction in relaxation time (τm) from 4.9 × 10–7 s to 3 × 10–7, 2.3 × 10–7, and 1.8 × 10–7 s was observed with increasing the Ar+ ion beam fluence. The reported enhancements in this work would open the road for appropriating the irradiated (PEO/CeO2) films for voltaic and energy storage applications.