In:
Japanese Journal of Applied Physics, IOP Publishing, Vol. 36, No. 10R ( 1997-10-01), p. 6426-
Abstract:
Doped CeO 2 –(CeO 2 ) 0.9 (Gd 2 O 3 ) 0.1 pellets were prepared using the glycine-nitrate process with various sintering times and sintering temperatures. Compositional and structural characterizations were carried out using X-ray diffraction (XRD) with CuKα radiation, a scanning electron microscope (SEM) and a Transmission electron microscope (TEM). Sintering and electrical characteristics were investigated using dilatometer measurement and the AC impedance analyser. Powder characteristics were also investigated by the BET method. Polycrystalline (CeO 2 ) 0.9 (Gd 2 O 3 ) 0.1 powders with specific surface areas of 19–23 m 2 / g were obtained. Green bodies from the synthesized powders after milling shrunk up to about 1470° C, above which they expanded with heating temperature, whereas those before milling shrank continuously up to a temperature of 1600° C. This difference might be attributed to the change of the packing density of the synthesized powders upon milling: from 25% without milling to about 40% after milling. Therefore the sintered (CeO 2 ) 0.9 (Gd 2 O 3 ) 0.1 bodies having a theoretical density of 7.25 g/cm 3 were considered to be obtained from the as-milled powders by controlling the sintering time at a sintering temperature higher than 1470° C in air. In the AC impedance measurements, the electrical resistivity of the (CeO 2 ) 0.9 –(Gd 2 O 3 ) 0.1 bodies, produced from as-milled powders, and sintered at 1500° C with increasing sintering time, showed the minimum total value at the sintering time of 10 h. The minimum total resistivity of the (CeO 2 ) 0.9 (Gd 2 O 3 ) 0.1 bodies sintered at 1500° C for 10 h seems to be obtained when the sum of the activation energy for the resistivities in the grain and at the grain boundary.
Type of Medium:
Online Resource
ISSN:
0021-4922
,
1347-4065
DOI:
10.1143/JJAP.36.6426
Language:
Unknown
Publisher:
IOP Publishing
Publication Date:
1997
detail.hit.zdb_id:
218223-3
detail.hit.zdb_id:
797294-5
detail.hit.zdb_id:
2006801-3
detail.hit.zdb_id:
797295-7
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