Nanocomposites by sol-gel and ion-exchange routes

Nanocrystalline materials are interesting both from the point of view of basic physics as well as technological applications. Preparation of nanocomposites is necessary to facilitate investigation of the effect of small size of a material on various physical properties. The method of preparing composites of nanosized metal particles dispersed in a glass matrix by the conventional melt-quench technique is reviewed. The versatility of sol-gel method in making nanocomposites is brought out. Results obtained on the metal organic route to certain glass-metal nanocomposites are described. The effectiveness of the ion exchange reaction followed by reduction treatment in the synthesis of ultra fine metal particles in a glassy environment is stressed upon. Finally, the glass-in-glass nanocomposites prepared by an ion exchange process and possessing very high electrical conductivity are discussed