Structural, DC Conductivity and Electric Modulus Studies of Polypyrrole Praseodymium Manganite Nanocomposites

Praseodymium Calcium Manganite (PCM) nanoparticles were synthesized by sol-gel method. Polypyrrole (PPy) and polypyrrole–praseodymium manganite nanocomposites (PPy/PCM) were synthesized by in-situ chemical polymerization method. Transmission electron microscope (TEM) confirmed good crystallinity with 42-63 nm average particle size. Scanning electron microscope (SEM) exhibited well-defined core structure of PPy and the PPy/PCM nanocomposites. X-ray diffraction (XRD) patterns of PPy showed amorphous nature and those of composites showed semicrystalline nature. UV-Vis spectroscopy was used to study the energy band gap for all the nanocomposites and hence they may find a place in wide band gap applications. The UV (231nm) and visible (363 nm and 377 nm) emissions were observed from the spectrum. DC conductivity was studied from 473 to 303 K for all the nanocomposites and found that conduction is of semiconductor type. Analysis of electric modulus confirmed the contribution from grain and grain boundary, non-Debye type relaxation and dc conductivity obeyed Correlated Barrier Hopping (CBH) model.