The morphology of nanoscale deposits of ruthenium oxide in silica aerogels

Ruthenium oxide was deposited an the internal surfaces of silica aerogel by solution impregnation of a Ru(III)tris-acetylacetonate solution followed b y reduction and oxidation. The structure of the Ru phase was determined by contrast-matching SANS, which allows independent collection of scattered in tensity from SiO2 and Ru oxide components of composite samples. The structu re of the Ru oxide deposit depends strongly on the oxidation temperature an d very little on the reduction temperature. The Ru oxide forms particles, r ather than a conformal layer, which coarsen from a few nanometers after oxi dation at room temperature to several tens of nm after oxidation at 250 deg rees C. (C) 1999 Acta Metallurgica Inc.