Magazine article Science News

Model Finds Clusters for New Materials

Magazine article Science News

Model Finds Clusters for New Materials

Article excerpt

Chemists typically create new materials by joining atoms together. But scientists are now turning their attention to a different kind of building block: clusters of atoms or molecules. Toward that end, two physicists have derived a recipe for clusters most likely to form a stable solid.

By fiddling with the numbers and types of atoms in a cluster, researchers can ensure that the cluster's atoms will hang together even when they move close to another cluster to form a new material, says Purusottam Jena of Virginia Commonwealth University in Richmond.

Jena and Virginia Commonwealth colleague Shiv N. Khanna modeled clusters containing 13 aluminum atoms or 12 aluminum atoms plus a carbon or silicon atom at the cluster's core. That single-atom substitution makes the cluster much more stable and therefore amenable to staying intact, they report in the Sept. 14 PHYSICAL REVIEW LETTERS.

A cluster acts like a giant atom, Jena explains. In both single atoms and clusters, electrons settle into specific energy levels. An atom becomes most stable when electrons fill up a level, so atoms tend to borrow or lend leftover electrons to empty or fill incomplete levels. When an atom joins a cluster, its excess electrons become the cluster's electrons. And, like an atom, the cluster becomes most stable with its energy levels filled, Jena says.

Thus, clusters work best when the leftover, or "valence," electrons total two, eight, 20, or 40 - numbers that fill energy levels. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.