Optoelectrical properties of polymer composite: Polystyrene-containing iron particles

The physical properties of polystyrene composites containing different concentrations of iron (0, 5, 10, 20 and 30wt.%) were studied as a function of ultraviolet (UV) wavelength, iron concentration, temperature, and applied field frequency. The absorption spectra were collected using the UV-spectrophotometry, and the electrical results were determined using the alternating current (AC) impedance method. Analysis of the optical absorption spectra results showed that the transition of energy electrons is direct in k-space and the optical energy gap decreases with iron content. The impedance was measured in the frequency range 50kHz-1MHz and temperature range 30-110C. It was found that the dielectric constant and the dielectric loss of the composites increase with iron concentration and decrease with the applied frequency. The AC conductivity of the composites increases with frequency, temperature, and iron concentration. The low value of the activation energies indicates that the composite of 30wt.% of iron nearly becomes a conductive material.