Investigations on Fe 3+ doped polyvinyl alcohol films with and without gamma (γ)-irradiation

Abstract

This paper deals with the preparation of pure and ferric chloride (FeCl 3) doped polyvinyl alcohol (PVA) films by solution casting method. Optical and electrical properties were systematically investigated. We have found the decrease in optical band gap energy of PVA films on doping FeCl 3. The optical band gap energy values in the present work are found to be 3.10 eV for pure PVA, 2 eV for PVA:Fe 3+ (5 mol%), 1.91 eV for PVA:Fe 3+(15 mol%) and 1.8 eV for PVA:Fe 3+(25 mol%). Direct current electrical conductivity ( σ) of pure, FeCl 3 doped PVA films in the temperature range 70–127 °C has been studied. At 387 K dc electrical conductivity of pure PVA film is 5.5795 μ Ω −1 cm −1, PVA:Fe 3+ (5 mol%) film is 10.0936 μ Ω −1 cm −1 and γ-Irradiated PVA:Fe 3+ (5 mol%) film for 900 CGY/min is 22.1950 μ Ω −1 cm −1. The result reveals the enhancement of the electrical conductivity with γ-irradiation. FT-IR study signifies the intermolecular hydrogen bonding between Fe 3+ ions of FeCl 3 with OH group of PVA.