Coprecipitation synthesis of doped lanthanum chromite

Journal Article · Wed Sep 01 04:00:00 EDT 1993 · Journal of Materials Research; (United States)

DOI:https://doi.org/10.1557/JMR.1993.2327· OSTI ID:5987207

De Guire, M R ^[1]; Dorris, S E; Poeppel, R B; Morissette, S; Balachandran, U ^[2]

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1. Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, Ohio 44106-7204 (United States)
2. Materials and Components Technology Division, Argonne National Laboratory, Argonne Illinois 60439 (United States)

Two coprecipitation methods were used to synthesize powder precursors of doped lanthanum chromite (La,Ca)(Cr,Co)O[sub 3]. The effects of synthesis method and calcination temperature on the composition, sintered density, and microstructure of pressed compacts of (La,Ca)(Cr,Co)O[sub 3] were studied by differential thermal analysis/thermogravimetric analysis, x-ray diffraction, scanning electron microscopy, and density measurement. The cation ratios in the precipitated solids were, with few exceptions, within experimental error of the desired compositions for all four components. Powders obtained by both techniques could be sintered to densities exceeding 93% at 1400 [degree]C. The highest densities were obtained with calcining temperatures from 450 to 700 [degree]C. The sintered microstructures exhibited uniform grain sizes averaging 3--5 [mu]m. The Cr(VI) compounds, CaCrO[sub 4] and La[sub 2]CrO[sub 6], were observed in all of the calcined powders. The possible role of these phases on chromite densification is discussed.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 5987207
• Journal Information: Journal of Materials Research; (United States), Journal Name: Journal of Materials Research; (United States) Vol. 8:9; ISSN JMREEE; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
CHEMICAL COMPOSITION
CHROMATES
CHROMIUM COMPOUNDS
COHERENT SCATTERING
COPRECIPITATION
DENSITY
DIFFERENTIAL THERMAL ANALYSIS
DIFFRACTION
DOPED MATERIALS
ELECTRON MICROSCOPY
FABRICATION
LANTHANUM COMPOUNDS
MATERIALS
MICROSCOPY
MICROSTRUCTURE
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POWDERS
PRECIPITATION
RARE EARTH COMPOUNDS
SCANNING ELECTRON MICROSCOPY
SCATTERING
SEPARATION PROCESSES
SINTERING
SYNTHESIS
THERMAL ANALYSIS
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION