Triple-component Fe3O4/bentonite/terthiophene nanocomposites for high-efficiency dielectric capacitors over a wide temperature range

In this study, novel nanocomposites with a ternary structure Fe 3 O 4 /Bentonite/Terthiophene, with different Fe 3 O 4 concentrations, were successfully prepared by the co-precipitation method. Different techniques, including XRD, TEM, SEM, XPS, AFM, and TGA-DTA, were applied to investigate the structural properties of the prepared samples. XRD and AFM results showed that the addition of Fe 3 O 4 into the Bent/TTh was accompanied with increasing the particles size, and the 5% Fe 3 O 4 /Bent/TTh showed the largest particles. TEM results displayed the porosity in the Bent/TTh improved after the addition of Fe 3 O 4 . The dielectric constant (ε′) and electrical conductivity (σ) of the prepared samples were also measured as a function of temperature (from 20 °C to 220 °C) and frequency (5 kHz to 8 MHz) to elucidate the impact of varying Fe 3 O 4 concentrations. The results showed that the addition of Fe 3 O 4 into Bent/TTh accompanied with increasing the conductivity from -19 to -9 σ.ohm -1 .cm -1 with increasing frequency (from 5KHz to 8MHz) and reducing dependence of electrical conductivity of Bent/TTh on the temperature, while the ε′ values decreased compared with Bent/TTh from 225 to 25. Also, the dielectric loss (ε′′) was significantly reduced after the addition of Fe 3 O 4 from 420 to 12. Based on the obtained results, the 10% Fe 3 O 4 /Bent/TTh nanocomposite is identified as the optimal candidate for high charge storage applications, owing to its maximum dielectric constant. Conversely, the 5% Fe 3 O 4 /Bent/TTh nanocomposite proves superior for applications requiring low energy dissipation, as it exhibits minimal dielectric loss across wide temperature and frequency ranges.