Calcium-doped lanthanum chromite powders were prepared by a complex polymerization method and their sintering behavior was investigated. The mixture solution of La(NO3)3·6H2O, Ca(NO3)2·4H2O, Cr(NO3)3·9H2O, citric acid and ethylene glycol was heated at 200oC to form a polymerized gel. When the precursor was heat-treated at 300oC, a lanthanum chromite phase was detected by XRD. The XRD peak of lanthanum chromite became sharp by heat treatment at 800oC. La0.8Ca0.2CrO3 powder exhibited the single phase of lanthanum chromite. However, CaCrO4 was detected besides lanthanum chromite in La0.7Ca0.3CrO3 powder. When carbon black powder was used as inert filler, the fine powder of submicrometre size was obtained. The fine powder of calcium-doped lanthanum chromite had a high sinterability. The relative density of a La0.8Ca0.2CrO3 sintered body was 96% at 1700oC in an Ar atmosphere.

Keywords: lanthanum chromite, complex polymerization method, fine powder, sinterability