报告题目：金属间化合物：从化学键到性能
      Intermetallic Compounds: from Chemical Bonding to Useful Properties
报告内容简介：Intermetallic compounds show physical properties interesting for applications, serving therefore as important components for materials design. An attempt to find a direct link between the properties and the crystal structure as well the atomic interactions for this group of inorganic substances leads not seldom to the conclusion, that there is a lack of reliable information on all three, crystal structure, bonding and properties, hindering studies on their relationship. Especially, chemical bonding in intermetallic compounds and its relation to the crystal structure is a rather open question. An application of Electron Localizability approach (ELI-D) opens access to the bond definition in real space, allows revealing of the – on first glance unexpected - relation between organometallic and intermetallic compounds and gives a possibility of Zintl-like electron counting for large group of intermetallic phases. This – in turn – yields a connection to the basic information about the band structure. The intermetallic clathrates attract the attention of material’s developers during the past decades due to their promising thermoelectric activity. The ELI-D approach allows differentiation of covalent and ionic contributions to the atomic interactions. With the new tools the formation of the lone pairs around the defects in the Ge framework in Ba8Ge43□3 was revealed, and the covalent Ba-Au interactions were detected in the clathrate Ba8AuxGe46-x-y□y. Both findings yield to the special features of the electronic DOS, which were confirmed by measurements of electronic and thermal transport. Bonding-caused features in the real structure of TmAlB4 yield new magnetic interactions and remarkable difference in the magnetic properties between the ideal and real material. Understanding of the bonding in intermetallic clathrates opens a way to novel redox-based preparation routes. So the hitherto unknown binary clathrates BaGe5, ternary clathrate Ba8Ni3.5Ge42.1□0.4 or the prototype of clathrate-II – Na24Si136 – were prepared and their transport properties were investigated. Another recent bonding-based concept dealing with the intermetallic phases is isolated-site model for catalysis. New catalysts for semi hydrogenation of acetylene – based on the well-crystallized intermetallic compounds GaPd and Al4Fe13 – were suggested employing the ideas of the covalent atomic interactions in intermetallic compounds.
报告人姓名：Yuri Grin
报告人简介：德国马普固体化学物理所所长、教授，德国德累斯顿工业大学教授
      Director and Professor of Max-Planck-Institut für Chemische Physik fester Stoffe, Dresden; Professor of Dresden Technical University， Germany
报告人单位：德国马普固体化学物理所，德国德累斯顿工业大学
     Max-Planck-Institut für Chemische Physik fester Stoffe, Dresden
报告时间：2014-03-31 09:00
报告地点：上海大学校本部东区材料楼520会议室