Sintering and microstructure

Most of the literature focuses on the aspects of sinterability and microstructure, but limited data on the electrical properties is available. Tok [152] reported a conductivity of 18.3 x 10-3 Scm-1 at 600°C for Gd0 jCeo.gOj 95, and we measured a high conductivity of 22 x 10-3 scm-1 for Sm0 2Cc08O 9 at the same temperature. Their activation energies are relatively low—less than 0.7 eV. Although conductivity data reported for doped ceria prepared with carbonate precipitation is varied from different authors [153-155], the conductivity is generally high and the activation energy is usually low for ceria electrolytes fabricated with this method. 

W. Hermel, M. Herrmann and I. Schulz, Sintering and Microstructure of Si3N4-Materials , Silicon Nitride 93, Edited by M. J. Hoffmann, P. F. Becher, G. Petzow, Trans tech Publications, 1993, 181-186. 

In summary, the experiments of Barringer and Bowen demonstrate clearly that substantial benefits can be achieved in sintering and microstructure control when the powder quality is carefully controlled and the powder packing is homogeneous, i.e., when careful attention is paid to the processing steps that precede firing. However, this fabrication route is not currently used in many industrial applications where mass production and low cost are important considerations. 

The sintering and microstructural evolution of ZnO powder compacts was studied by Chu et al. (9) over a wide range of constant heating rates (0.5 to 15°C/... 

Kara F, Sener O. Improvement of sintering and microstructural homogeneity of a diphasic muUite. J. Eur. Ceram. Soc. 2001 21 901-905... 

Muthuraman M., Patil K.C. Synthesis, properties, sintering and microstructure of sphene, CaTiSiOj A comparative study of coprecipitation, sol-gel and combustion processes. Mater. Res. Bull. 1998 33 655-661... 

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