Paper No. 95-10
Presentation Time: 10:15 AM
FROM CLUSTERS TO NANOPHASES TO MINERALS
Recent structural, kinetic, and thermodynamic studies have emphasized the prevalence of nanometer sized clusters in aqueous solution as precursors to the precipitation of nanophases that gradually coarsen to form well crystallized mineral phases. Using carbonates, aluminum oxides, and uranyl peroxide phases as examples, this presentation traces the energetic and structural evolution of such processes. It is becoming increasingly clear that such clusters already possess many of the structure and bonding features characteristic of the emerging solids and the progression from prenucleation cluster to nanophase to bulk forms a rich downhill energy landscape , enabling the formation of different polymorphs triggered by small changes in compositional parameters and temperature. Nanoclusters are the stem cells of mineralogy!