T_cSUH Special Seminars

Friday, September 26, 2008

Room 102, University of Houston Science Center

12:00 PM - 01:00 PM

Atomic structures are generally described by crystallography, which is entirely based on planar periodicity. However such a method largely fails in describing complex atomic structures such as complex metallic alloys and disordered systems. Alternative to planar periodicity is spherical periodicity arising from resonance between electron wave and static atomic strictures, which has been proven widely present in disordered systems. One unique advantage is that only local 1st-neighbor cluster structure information is needed to depict the global structure. It implies that a structure, no matter how complex it can be from crystallographic viewpoint, consists simply of a cluster plus a few glue atoms, or in cluster formula (cluster)1(glue atom)x. Such a cluster-plus-glue-atom model is applied to give the composition formulas of a variety of complex structures such as crystalline intermetallic compounds, bulk metallic glasses, quasicrystals, and even multi-element solid solution limit alloys.