纳米结构材料

纳米材料（ＮｓＭ）是这样一类固体，其结构单元（大多为结晶体）至少在一个方向上具有数个纳米的特征尺寸。按照结构单元的形状、化学成分可将其划分为１２种类型。ＮｓＭ的结构及性能不同于具相同化学成分的单晶体和玻璃。这种差别归因于晶体尺寸的减少、晶体形状（薄片、针和等轴）引起的维数效应以及结构单元之间界面的密度下降和配位数的变化。本文讨论了支持上述观点的某些实验结果，描述了金属、大分子、半导体纳米材料的技术

NANOSTRUCTURED MATERIALS

Nanostructured materials (NsM) are solids composed of structural elements-mostly crvstaltites-with a characteristic size (in at least one direction) of a few nanometers.NsM may be classified into twelve groups according to the shape and chemical com-position of their constituent structural elements. The atomic structu re and properties of NsM deviate from the ones of a single crystal and / or glass with the same chemical composition. This deviation results from the reduced size of the crystallites.dlmensionality effects due to the shape of the crystallites (thin plates. needles or equiaxed shape). and the reduced densitV and / or modified coordination numbers in the interfaces between the structural elements. Some of the experimental observations supporting these ideas are discussed. Technological applications of metallic .macromolecular and semiconducting NsM are described,