The effects of additives and precipitants on the syntheses of doped
LaCrO3 (lanthanum chromites) were studied by hydrothermal reaction
at temperature ranges of 100℃ to 230℃. LaCrO3 nanopowders were
synthesized by hydrothermal methods using several types of
precipitants such as NaOH, KOH, NH4OH, and NH2CONH2.
The influence of Sr, Ca and Co doping on the lanthanum chromites prepared by
hydrothermal method were investigated. The synthesized nanopowders were
characterized by means of XRD, SEM and densitometer. The electrical
conductivity of the doped LaCrO3 was studied at 750℃ in air by a DC
four point probe method.The particles size of undoped LaCrO3 nanopowder was approximately 100nm when using KOH as a
precipitant. The relative density of lanthanum chromite doped with calcium and
cobalt is over 97%. The highest electrical conductivity of La0.62Ca0.38Co0.18Cr0.82O3 was 32.75 S/cm at 750℃ in air, which is 30 times higher than undoped LaCrO3.
The density and electrical conductivity are increased by doping cobalt and
calcium on the LaCrO3.
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