Low-Temperature Sintering of La(Ca)CrO3 Powder Prepared through the Combustion Process

Authors


  • R. Cutler—contributing editor

†Author to whom correspondence should be addressed. e-mail: rdp.nano@gmail.com

Abstract

Ultrafine La(Ca)CrO3 (LCC) powder was prepared through the glycine–nitrate gel combustion process. It was shown for the first time that the use of relatively inexpensive CrO3 as a starting material for chromium has potential for the bulk preparation of sinter-active LCC powder. As-prepared powder, when calcined at 700°C, resulted in LCC along with a small amount of CaCrO4. The calcined powder was found to be composed of soft agglomerates with a particle size of ≈70–290 nm. The cold pressing and sintering of the calcined powder at 1200°C resulted in the mono-phasic La0.7Ca0.3CrO3 with density ≈98% of its theoretical value. This is the lowest sintering temperature ever reported for La0.7Ca0.3CrO3. The conductivity of the sintered La0.7Ca0.3CrO3 at 1000°C was found to be ≈57 S/cm in air. The sintering and electrical behavior achieved for La0.7Ca0.3CrO3 may find application as an interconnect material for high-temperature solid oxide fuel cells if problems with chemical expansion and poor conductivity in fuel can be overcome.

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