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

Abstract

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. UVVis 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.