Synthesis of LaCrO<sub>3</sub> from Complex Precipitation and Its Electrical Conductivity

Abstract

A well-crystallized LaCrO3 powder with a primary particle size of about 1μm was synthesized through the complex precipitation process; obtaining the precipitate of complex hydroxide from an NaOH aqueous solution of Cr(NO3)3 by adding LaCl3 and then heating the precipitate up to 700°C. The LaCrO3 single-phased powder was prepared from the precipitate obtained by adding less amount of La3+ than the equimolar ratio, but an excess adding of La3+ resulted in La2CrO6 with LaCrO3. From density measurements and SEM observations, the powder thus prepared has no remarkable sinterability. However, the electrical conductivity (about 0.069S/cm) of the specimen, of which relative density was as low as 57%, was comparable with those reported on the dense specimens. The temperature dependence of conductivity of the present specimen showed a break around 180°C. The activation energy was determined as 0.20 and 0.23eV above and below 180°C, respectively.