Structural, Optical, Electrical and Antibacterial Properties of Fe-Doped CeO2 Nanoparticles

This paper reports the structural, optical and antimicrobial study of Ce1−xFexO2−δ (0≤ x ≤20) nanoparticles (NPs) synthesized using a microwave-assisted hydrothermal method. The XRD pattern analysed using Rietveld refinement method clearly infers that all the samples exhibit single phase nature and exclude the possibility of an impurity phase. The lattice parameters and unit cell volume were found to decrease with an increase in Fe-doping content in CeO2 nanoparticles. The crystalline size determined using XRD pattern and TEM micrographs was found to decrease with Fe doping in CeO2. Selective area electron diffraction (SAED) pattern also demonstrated the crystalline nature of the Fe-CeO2 nanoparticles. Optical properties studied using UV–vis spectroscopy indicated that band gap decreased with an increase in Fe doping. The electrical properties have been investigated via dielectric constant, dielectric loss and AC conductivity. The dielectric constant was found to increase in the Fe-doped CeO2 nanoparticles, while AC conductivity was found to be reduced, which shows good dielectric behaviour of the Fe-doped CeO2 nanoparticles. The antibacterial activity of the synthesized NPs was achieved under ambient conditions with different bacteria, and the results showed that the properties were different for both bacteria. The antimicrobial activity reflects the possibility to develop Fe-doped CeO2 NPs as antibacterial agents against extensive microorganisms to control and prevent the spread and persistence of bacterial infections.

STUDY OF AC/DC CONDUCTIVITY OF POLY VINYL CHLORIDE PVC AND EC, EC/PVC CONDUCTION MECHANISMS RESPONSIBLE FOR THE CONDUCTIVITY

The current work investigates the AC and DC conductivity constant of PVC and EC samples (3:1) at many constant temperatures in the frequency range (323K to 363K). The ndings were presented in graph form. The dielectric constant increases with temperature increase at constant frequencies, Dielectric constant decreases with frequency increases, and AC conductivity increases with frequencies at different constant temperatures. The frequencies reach almost saturation values as the ultimate 1MHz value reaches. The AC conductivity increases with the increase in frequency has been observed.

Effect of Potassium Alum and Carbon Black Nanoparticles on Casted Peo Composite: Phase Angle, Dielectric Constant, Impedance and AC Conductivity

The electrical characteristics of hybrid polymer thin films consisting of conductive carbon black (CB) nanoparticles (0.1wt%) doped in poly(ethylene oxide) (PEO) filled with electrolyte potassium alum salt at varied concentrations were studied. For varied potassium alum concentrations and fixed content of conductive carbon black of concentration (0.1 wt. percent), the AC electrical characteristics were studied in the frequency range (3kHz - 5MHz) and temperature range (30 oC - 55 oC). Thin film physical constants such as dielectric constant, dielectric loss, AC conductivity, and impedance have been recorded. These measured amounts were discovered to fluctuate with potassium alum concentration, applied field frequency, and temperature. With increasing potassium alum content, frequency, and temperature, the AC conductivity (ac) increases. Dielectric constant (ε') and dielectric loss (ε'') of the composites increase with potassium alum concentration and decrease with frequency.

Structural, impedance, dielectric and optical characteristics of Cd- substituted Zn (1-x) CdxO nanoparticles at low temperatures

Nanocrystalline Cd substituted ZnO nanoparticles with common formula Zn (1-x) CdxO (x = 0%, 3%, 6%, and 10%) were fabricated by a co-precipitation technique. X-ray diffraction (XRD) and scanning electron microscopy (SEM) was used to investigate the microstructures and morphology of synthesized nanoparticles at room temperature. The outcome of the x-ray diffraction (XRD) study supports the existence of wurtzite crystal structure for ZnO, and Cd substituted ZnO samples conformed that substituted Cd ions are catching up Zn site. The morphological assessments of the fabricated nanoparticles indicated that the nature of the nanoparticles is a slightly hexagonal and mostly spherical shape with size ranges 46-55 nm. The electric impedance of the samples was measured in a wide range of frequency 100Hz–2MHz at different temperatures (140 K-260 K) using an LCR meter. It was observed that the dielectric constants (ἐ), (ε´´), loss tangent (tanδ), and ac conductivity of pure and Cd substituted ZnO nanoparticles depended on frequency. The calculations of dielectric measurement showed that the parameters (ἐ), (ε´´), loss tangent (tanδ) decreased with the increase in frequency. But the ac conductivity enhanced with the frequency, whereas the values of the above parameters increased with the temperature rise. The dielectric parameters are also found to improve with the increase in Cd concentrations. The correlated barrier-hopping (CHB) model dominated in ac conductivity. The reduction in the bandgap was also observed with Cd concentration.