Nanocrystals of metals, semiconductors and oxides: Novel synthesis and applications*

Films of nanocrystals such as Au, Ag and Pd, semiconducting sulphides such as CdS, ZnS and CoS, and oxides such as Fe 2 O 3 and CuO have been prepared by employing reactions at liquid-liquid (organic-aqueous) interfaces. In this method, a suitable organic derivative of the metal taken in the organic layer reacts at the interface with the appropriate reagent present in the organic layer. Two typical applications of nanocrystals pertaining to magnetic devices and dip-pen lithography are briefly presented.