Structure and properties of nanometer-sized materials

Abstract

Nanometer-sized materials are solids which may be considered as a dense ensemble of atomic clusters with a diameter of a few nanometers. Depending on whether the individual clusters have a crystalline or a glassy structure, nanocrystalline materials or nanometer-sized glasses are formed. Nanocrystalline materials (NCM) are single or multiphase ploy-crystals, the crystal size of which is in the order of a few (typically 1 to 10) nanometers. These materials are of interest for the following three reasons: If small (1 to 10 nm diameter) glass particles are consolidated, a new type of glasses, called nanometer-sized glasses, are obtained. These nanometer-sized glasses differ structurally from conventional glasses. Their short range order comprises nearest or next nearest neighbours only. The atomic arrangement beyond nearest neighbours seems random.