AC and DC electrical studies on cobalt chloride doped PVA – PVP blend films

• Main Authors: Baraker, Basavarajeshwari M., Lobo, Blaise
• Format: Conference Proceeding
• Language: English
• Subjects: Chain mobility; Chlorides; Cobalt; Dielectric relaxation; Direct current; Doping; Electrical measurement; Electrical resistivity; Frequency response; Nyquist plots; Parameters; Polyvinyl alcohol; Temperature dependence
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0009039

The temperature dependent dielectric relaxation processes in films of polyvinyl alcohol (PVA) blended with polyvinyl pyrrolidone (PVP) and doped with cobalt chloride (CoCl2) at 0.0 wt% and 2.4 wt% doping levels (DL) have been studied using AC and DC electrical measurements. The frequency response of dielectric parameters of these samples has been studied with variation in temperature, from 303 K up to 343 K, and also at different fixed frequencies (from 12 Hz up to 200 kHz). The study of Nyquist plots for these samples show that there is a decrease in bulk resistivity of these samples with an increase in temperature, which is attributed to thermally induced increase in the mobility of polymer chains. A ten times enhancement in the value of bulk conductivity is measured for the 2.4 wt% CoCl2 doped PVA-PVP blend film, when compared to that of un-doped (0.0 wt% DL) PVA-PVP blend film is attributed to mobility of dopant induced ionic species. Temperature dependence of dielectric parameters at different frequencies has been studied. From the temperature variation of DC electrical conductivity, the activation energy has been determined using Arrhenius equation. DC electrical measurement reveals that there is a significant enhancement in electrical conductivity after doping PVA-PVP with CoCl2, and the time evolution studies reveal that ionic conduction is the dominant conduction mechanism in films of CoCl2 doped and the un-doped PVA-PVP blend films.