Sintering inhibition and reactions between La(Ni,Co)O3 and BaTiO3: powder mixtures

Powder mixtures of BaTiO3 and LaNi0.6Co0.4O3 have been investigated by heating stage microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction in order to study the densification behavior and compound formation. By heating microscopy it was demonstrated, that the addition of a few per cent of each material to the other strongly influences the shrinkage of the ceramics. SEM investigations showed a pronounced change in grain size and porosity throughout the whole range of powder mixtures. X-ray diffraction proved the formation of a solid solution between BaTiO3 and LaNi0.6Co0.4O3 as well as the formation of secondary phases. From these results it is concluded, that densification problems arise mainly from compound formation and a preferred diffusion of Ti from the BaTiO3 to the LaNi0.6Co0.4O3.