Morphological, structural, electrical impedance, and equivalent circuit analysis of polypyrrole/barium substituted lanthanum manganite (La0.7Ba0.3MnO3) perovskite nanocomposites

The article presents the impedance analysis of polypyrrole (PPy)/La_0.7Ba_0.3MnO₃ (LBM) nanocomposites synthesized by in situ chemical oxidation method. The morphology and crystal structure were analyzed by Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) techniques. Vibration modes were analyzed using Fourier Transform Infrared spectroscopy (FTIR). The impedance behavior of the compounds was studied using an impedance analyzer in the frequency (100 Hz − 5 MHz) and temperature (30 °C − 90 °C) variation mode. Results of SEM and TEM for PPy, LBM, and PPy-LBM nanocomposites show spherical, rhombic and granular structures respectively. FTIR shows the presence of respective elements to be present for the formation of PPy, LBM, and PPy-LBM compounds. XRD patterns of PPy, LBM, and PPy-LBM nanocomposites show amorphous, orthorhombic, and semicrystalline phases respectively. The Real part of impedance shows decreasing value with frequency and the imaginary part of impedance shows the relaxing nature of the compounds. Cole − Cole analysis reveals the resistance contribution from grains and grain boundary. The equivalent circuit elucidated gives the combination of resistor and capacitor being parallel along with constant phase element and Warburg effects. The study helps us to understand the electric behavior of the samples whether capacitive or resistive type for which further studies can be conducted for sensor, anticorrosion coating, and spintronic applications.