In physics, the term clusters denotes small, multiatom particles. As a rule of thumb, any particle of somewhere between 3 and 3*10^7 atoms is considered a cluster. Two-atom particles are sometimes considered clusters as well^{[citation needed]}. Properties In chemistry and physics, an atom (Greek ἄτομος or átomos meaning indivisible) is the smallest particle still characterizing a chemical element. ...

Cluster science was born in the 1980s. One purpose of the research was to study the gradual development of collective phenomena which characterize a bulk solid. These are for example the color of a body, its electrical conductivity, its ability of absorb or reflect light, and magnetic phenomena such as ferro-, ferri-, or antiferromagnetism. These are typical collective phenomena which only develop in an aggregate of a large number of atoms.

It was found that collective phenomena break down for very small cluster sizes. It turned out, for example, that small clusters of a ferromagnetic material are super-paramagnetic rather than ferromagnetic. Paramagnetism is not a collective phenomenon, which means that the ferromagnetism of the macrostate was not conserved by going into the nanostate. The question then was asked for example “How many atoms do we need in order to obtain the collective metallic or magnetic properties of a solid”? Soon after the first cluster sources had been developed in 1980, an ever larger community of cluster scientists was involved in such studies. Ferromagnetism is a phenomenon by which a material can exhibit a spontaneous magnetization, and is one of the strongest forms of magnetism. ... Simple Illustration of a paramagnetic probe made up from miniature magnets. ...

This development led to the discovery of fullerenes in 1986 and carbon nanotubes a few years later. Buckminsterfullerene (C60) Fullerenes are molecules composed entirely of carbon, taking the form of a hollow sphere, ellipsoid, or tube. ... An electronic device known as a diode can be formed by joining two nanoscale carbon tubes with different electronic properties. ...

In science, a lot is known about properties of the gas phase; however, comparatively little is known about the condensed phases (the liquid phase and solid phase.) The study of clusters attempts to bridge this gap of knowledge by clustering atoms together and studying their characteristics. If enough atoms were clustered together, eventually one would obtain a liquid or solid. This article or section does not adequately cite its references or sources. ... In the physical sciences, a phase is a set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties (i. ... A liquid will usually assume the shape of its container A liquid is one of the main states of matter. ... For other uses, see Solid (disambiguation). ... Properties For alternative meanings see atom (disambiguation). ...

The study of atomic and molecular clusters also benefits the developing field of nanotechnology. If new materials are to be made out of nanoscale particles, such as nanocatalysts and quantum computers, the properties of the nanoscale particles (the clusters) must first be understood. Buckminsterfullerene C60, also known as the buckyball, is the simplest of the carbon structures known as fullerenes. ... Molecule of alanine used in NMR implementation of error correction. ...

External links

http://cluster-science.net - scientific community portal for clusters, fullerenes, nanotubes, nanostructures, and similar small systems

See also

• Cluster chemistry