120 MeV Si¹⁰⁺ ions induced modifications of PEO/SnO₂ composites

Abstract

Polymer nanocomposite electrolyte films based on poly (ethylene oxide)/NaI and nano-tin oxide (SnO₂) as filler were prepared by the solution casting technique. The effect of 120 MeV Si¹⁰⁺ ion irradiation on the conductivity of the films has been studied. Irradiation affects the structure of materials at different scales, thus changing its physical and chemical properties. The samples have been characterized by means of X-ray diffraction (XRD), impedance gain-phase analyzer and infrared spectroscopy (Fourier transform infrared spectroscopy). Structural, electrical and dielectric properties were studied as a function of frequency, filler concentration and ion fluence (1×10¹¹ and 1×10¹² ions/cm²). The XRD studies reveal the amorphization of polymer nanocomposite electrolytes upon ion irradiation. Ionic conductivity is observed to increase with increase in filler concentration up to 15% of filler and then decreases for 20% of filler. Ionic conductivity increases significantly by irradiation with lower fluence, while when fluence is increased further conductivity decreases, which is explained in terms of amorphization of the polymer composite when irradiated with lower fluence and increase in crystallinity on further increase in ion fluence. The conductance spectra show two distinct regions: a dc plateau and a dispersive region. Complex impedance analysis shows the existence of bulk and material–electrode interface properties of the composites.

Keywords:

• polymer nanocomposite electrolyte
• ion irradiation
• XRD
• impedance spectroscopy
• FTIR