Microemulsion mediated synthesis of BaTi03-Ag nanocomposites

Abstract

BaTiO3 - Ag composite nanopowders were synthesized via microemulsion mediated synthesis through the hydrolytic decomposition of mixed metal alkoxide solutions as precursor for the BaTiO3 and the reduction of silver nitrate in the presence of polyvinylpyrrolidone (PVP) as source for the Ag nanoparticles. The X-ray diffraction (XRD) patterns indicate that BaTiO3 and Ag phases were successfully synthesized in the composite powders. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that the synthesized BaTiO3 nanoparticles were aggregates of nanosized primary particles as small as 10 nm in diameter and the average particle size of nanocrystalline Ag was about 100 nm. Calcination and sintering studies reveal that there exists a difference in the sintering behaviour of BaTiO3 and Ag in the composite nanopowders. Thermogravimetric analysis (TGA) shows weight losses due to the burnout of organic residues arising from the synthesis, the release of water from the surface and separation of hydroxyl ions from the lattice of BaTiO3 nanoparticles. A dilatometric study of BaTiO3-Ag composite confirmed a strong difference in the shrinkage behaviour compared to that of the pure BaTiO3 obtained by microemulsion mediated synthesis. .