Clusters and cluster-assembled materials

Abstract

92-132059 2 95 18 wo33;: Review of Work To DateOur work falls naturally into three categories: i) local density calculations of cluster structures and the development of classical potentials, (ii) simulations of thermodynamic properties of clusters and their fusion, and (iii) macroscopic (continuum theory) modeling of the sintering process. These topics will be addressed in turn. Although the nominal focus of the proposal is on sintering processes, many issues important to sintering are generic in nature and thus also important in other areas of cluster science. These issues have been approached from a broad perspective, leading to results which impact the whole field of clusters and cluster-assembled materials. We have concentrated on Al, which is a "typical" free electron metal, and Cu, as a representative transition metal atom. For Al, we have carried out extensive Car-Parrineflo and DVM calculations for clusters containing up to 55 atoms. Larger clusters, containing up to 2000 atoms, were studied quantum-mechanically using a jellium model. For Cu, DVM calculations for clusters containing up to 13 atoms have served as a basis for improving existing, efficient but very approximate "embedded atom method" (EAM) potentials. The results of the calculations 2