Abstract
This review article focuses on the sol-gel preparation of high temperature superconducting oxides wherein different classes of gel technologies were utilized. These involve: 1) the sol-gel route based upon hydrolysis-condensation of metal-alkoxides, 2) the gelation route based upon concentration of aqueous solutions involving metal-chelates, often called as "chelate gel" or "amorphous chelate" route, and 3) the organic polymeric gel route. This paper reviews the current status of these sol-gel processes, and illustrates the underlying chemistry involved in each sol-gel technology. It is demonstrated that the chemical homogeneity of the gel is often disturbed by the differences in the chemistries of the cations. Prior to gelation the starting precursor solution containing various forms of metal-complexes must be chemically modified to overcome this problem. Illustration of a variety of strategies for success in obtaining a homogeneous multicomponent gel with no precipitation is focal point of this review article.
Original language | English |
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Pages (from-to) | 7-55 |
Number of pages | 49 |
Journal | Journal of Sol-Gel Science and Technology |
Volume | 6 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1996 Jan 1 |
Externally published | Yes |
Keywords
- Amorphous chelate gel
- Chemical homogeneity
- High temperature superconducting oxides
- Metal alkoxides
- Multicomponent gel
- Organic polymeric gel
- Polymerized complex method
- Sol-gel method
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Chemistry(all)
- Biomaterials
- Condensed Matter Physics
- Materials Chemistry