Hydrothermal synthesis and sintering of lanthanum chromite powders doped with calcium

Precursor La-Ca gels of LaCrO3, La0.9Ca0.1CrO3 and La0.8Ca0.2CrO3 were prepared by coprecipitation and then crystallized under hydrothermal conditions. Under these conditions, mono dispersed nanosized ( < 300 nm) powders of LaCrO3 and its solid solutions doped with calcium were obtained at temperatures between 350 and 425degreesC. The powders were sintered in air at a temperature range of 1200-1500degreesC for intervals between I and 5 h. A maximum apparent density of 97.66% was preferentially achieved by pellets with the larger amount of Ca, La0.8Ca0.2CrO3, sintered at 1400degreesC for 5 h in air atmosphere. The average grain size measured on sintered specimens was of 6 mum. (C) 2004 Elsevier B.V. All rights reserved.