ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Factors, including pH, coprecipitating medium, and temperature, for preparing CaLa2S4 powder were investigated. The precursors obtained by rapid precipitation in an aqueous solution at 25 °C had a homogeneous morphology of minute dentrites, and showed little or no CaS in the X-ray diffraction (XRD) patterns after sulphurization at 950 °C for 24 h. The particle size of the precursors or sulphides obtained in the vicinity of isoelectric point of pH=7.8 had a broad distribution, while that obtained at pH〉9.24 had a narrow distribution. The precursors obtained in hydrous ethanol were a mixture of spherical, flaky and acicular particles in morphology, but all showed calcium deficiency. Interconnected particles were obtained in anhydrous ethanol at pH=6.81 and 25 °C with a highly homogeneous composition. No CaS phase was determined by XRD after sulphurization at 950 °C for 24 h. The CaLa2S4 powders obtained in both aqueous and anhydrous ethanol solutions were sintered, and a translucent pellet was obtained.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01151657
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