文档介绍：Nobel Prizeand the Nobel Prize medal design mark are registrated trademarks of the Nobel Foundation5 OKTOBER 2011Scientific Background on the Nobel Prize in Chemistry 2011THE DISCOVERY OF QUASICRYSTALSTHE ROYAL SWEDISH ACADEMY OF SCIENCEShas as its aim to promote the sciences and strengthen their influence in 50005 (LILLA FRESCATIV?GEN4 A), SE-104 05 STOCKHOLM, SWEDENTEL +46 8 673 95 00, FAX +46 8 15 56 70, ******@:// (11) The Discovery of Quasicrystals The Nobel Prize in Chemistry 2011 is awarded to Daniel Shechtman for the discovery of quasicrystals. Background Solid state matter always displays substantial short-range and long-range order to various degrees. Short-range order is imposed by the typical local bonding requirements of chemistry. Even in materials such as silica glass, which are normally considered to pletely amorphous, substantial local order is present: Each silicon atom is tetrahedrally surrounded by four oxygen atoms at ?, and the typical oxygen–oxygen separation is ?. While it is possible to detect one or two more distinct structural traits in silica glass, the material lacks the hallmark of crystallinity: long-range order. Ever since the work of Abbé Haüy in 17841, where he showed that the periodic repetition of identical parallelepipeds (molécules intégrantes, now known as unit cells) can be used to explain the external shape of crystals, long-range order has been assumed to be inextricably linked to translational periodicity. Hence, the classical definition of a crystal is as follows: A crystal is a substance in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating three-dimensional , this means that a crystal is infinite, and given the size of the unit cell (tens to hundreds of ?ngstr?ms) parison to the size of the physical crystal (hundreds of microns), practically, this is not too far off the mark. The vast majority of the unit cells form the