In:
Journal of Materials Research, Springer Science and Business Media LLC, Vol. 7, No. 9 ( 1992-09), p. 2349-2354
Abstract:
The CeO 2 -added Y–Ba–Cu–O oxides were prepared by two different processes, the conventional solid-state reaction process and the partial melt process using powders, to examine the effect of the dopant on microstructure, microhardness, and superconductivity. In the solid-state reacted sample, most of the added CeO 2 was converted to a form of BaCeO 3 , but some might enter into the 1-2-3 phase, resulting in the orthorhombic-to-tetragonal phase transition that accompanied the disappearance of twin structure in 1-2-3 grains. In the partially melted sample, however, the phase change was not observed up to 5 wt. % of CeO 2 . All the added CeO 2 in these samples was consumed to form only BaCeO 3 which was finely dispersed in large 1-2-3 grains during the peritectic reaction stage. The zero resistance temperature (T c ) of the solid-state reacted sample gradually decreased with increasing CeO 2 content due to the phase change and the formation of BaCeO 3 , whereas the T c of the partially melted sample was nearly constant regardless of CeO 2 content up to 5 wt. %, owing to the separation of the second phase from the 1-2-3 superconducting phase. Microhardness of the partially melted sample increased with increasing CeO 2 content. The strengthening effect appears to come from the composite system where the fine BaCeO 3 particles are dispersed in a 1-2-3 matrix.
Type of Medium:
Online Resource
ISSN:
0884-2914
,
2044-5326
DOI:
10.1557/JMR.1992.2349
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
1992
detail.hit.zdb_id:
54876-5
detail.hit.zdb_id:
2015297-8
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