ABSTRACT
The sol-gel process is a chameleon technology. Fifteen years ago, when the process enjoyed a resurgence in interest, the emphasis was on the duplication of ceramics and glasses which could be prepared by conventional means [ 1-3]. Scientific curiosity about the sol-gel process was based on the purity of the starting materials [4] and the generally lower temperatures for processing [5]. Along with other chemical methods for processing oxides, a large increase of conferences and reports occurred on this subject. The titles of these conferences tell the story of what was expected of sol-gel processing. On the one hand, solgel processing was a major part of the Materials Research Society Symposium series 'Better Ceramics through Chemistry', indicating no doubt that sol-gel processing leads to better ceramics [6-10]. On the other hand, sol-gel processing contributed to 'ultrastructure processing' which had the implication that solgel processing could be seen in the larger scheme of things where processing, properties, and performance are all linked [ 11-15]. There is mounting evidence that sol-gel processing makes better materials and that it will have a lasting role in advanced materials.
