Sintering Behavior of Doped Lanthanum and Yttrium Manganite

Abstract

The sintering behavior of doped manganite powders was found to be highly dependent on changes in calcination conditions and A/B cation ratio. Coarsening of combustion synthesized powders by calcination allowed for higher green densities in dry‐pressed compacts, which resulted in higher sintered densities for powders calcined in the temperature range 800°‐1200°C. Sintered densities decreased for calcination temperatures greater than 1200°C. Preparation of manganites with a deficiency of A‐site cations improved the densification behavior substantially. This effect was attributed to an increased concentration of A‐site vacancies which enhanced the diffusion of A‐site cations during sintering. Modification of doped manganites by alteration of composition and calcination conditions allowed their sintering shrinkage to be “tailored” to more closely match the shrinkage of yttria‐stabilized zirconia.