Synthesis, Characterization and Structural Properties of Ni0.9Bi0.1Fe1.9Co0.1O4 /Polypyrrole Nanocomposites

Abstract

Polypyrrole (PPy) was synthesized via a chemical oxidative polymerization route using 
pyrrole monomer in the presence of different oxidizing agents. In parallel, 
hexagonal ferrite nanoparticles with the chemical composition Ni0.9Bi0.1Fe1.9Co0.1O4 
(x= 0.1, 0.2 and 0.3) were successfully prepared using the sol–gel auto-combustion 
technique. Analytical-grade precursors, including nickel nitrate, cobalt nitrate, 
ferric nitrate, bismuth nitrate, and citric acid, were utilized without further 
purification. Stoichiometric quantities of the metal nitrates were accurately 
weighed and dissolved in ethylene glycol to produce a homogeneous salt solution. 
Citric acid was subsequently introduced as a chelating agent while maintaining a 
cation-to-citric acid molar ratio of 1:1.5. The pH of the resulting solution was 
adjusted to 7.0 through the dropwise addition of ammonia solution to facilitate gel 
formation and ensure uniform metal ion distribution prior to auto-combustion 
synthesis. The structural, morphological, compositional, and magnetic properties of 
the synthesized Ni0.9Bi0.1Fe1.9Co0.1O4 nanocomposites were investigated using Fourier 
Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron 
Microscopy (FESEM), and Energy Dispersive X-ray Spectroscopy (EDX). FTIR 
analysis confirmed the successful formation of the polymer-ferrite composite 
structure, while EDX spectra verified the elemental composition of the synthesized 
materials. FESEM micrographs revealed that the ferrite nanoparticles were 
uniformly and completely encapsulated by the polypyrrole matrix. Magnetic 
hysteresis measurements further demonstrated low coercivity values, confirming 
that the synthesized nanocomposites exhibit soft magnetic behavior suitable for 
advanced electromagnetic and electronic applications.