U.S.-Germany Cooperative Research on the Correlation betweenthe Nonmetal to Metal Transition in Clusters and at Surfaces

9300238普卢默该奖项支持田纳西大学的E. Ward Plummer教授、锡拉丘兹大学的Peter Dowben教授和德雷塞尔大学的N. John DiNardo教授与三位德国同行：马尔堡大学的Klaus Rademann教授和Ourania Rademann博士以及柏林自由大学的Eckart Ruhl博士在凝聚体物理学方面进行合作。他们合作研究的目的是对简单金属中非金属向金属转变的基本机制进行研究。该合作计划将三位对二维和固体表面非金属跃迁进行了大量研究的美国实验学家与三位对团簇跃迁进行了补充研究的德国实验学家聚集在一起。这项研究需要在同步加速器光源上进行大量的实验工作，以及使用其他非常专业的分析设备。德国合作者能够提供柏林的德国设施BESSY，而美国合作者将安排在美国国家同步加速器光源和其他美国设施进行联合工作，这些设施适合于表面岛屿和表面聚集体中非常复杂的碱金属特征。美国和德国的博士后和研究生将参与合作研究。随着团簇大小的增加，过渡金属团簇和聚集体表现出非金属到金属的转变。在固体表面的过渡金属层中也观察到类似的转变。到目前为止，为了证明金属和非金属在团簇和表面上的过渡之间的直接联系所需要的深入研究，只成功地对一种金属——汞进行了研究。这些研究人员建议通过对碱金属的过渡进行必要的比较研究来扩大这一知识基础。由于已有关于表层碱b行为的数据，联合研究将主要集中在簇中的转变上。这项研究的结果将有助于理解金属和非金属之间行为差异的基础。＊＊＊

9300238 Plummer This award supports Professors E. Ward Plummer of the University of Tennessee, Peter Dowben of Syracuse University, and N. John DiNardo of Drexel University to collaborate in condensed matter physics with three German counterparts: Professor Klaus Rademann and Dr. Ourania Rademann of the University of Marburg and Dr. Eckart Ruhl of the Free University of Berlin. The purpose of their cooperative research is to develop a picture of the fundamental mechanisms for the nonmetal to metal transition in the simple metals. The collaborative plan brings together three U.S. experimentalists who have done substantial research on the nonmetal transition in two dimensions and at solid surfaces to work with three German experimentalists who have done complementary research on the transition in clusters. The research requires substantial experimental work at a synchrotron light source, as well as access to other very specialized analytical equipment. The German collaborators are able to provide access to the German facility known as BESSY, in Berlin, while the U.S. collaborators will arrange for joint work at the U.S. National Synchrotron Light Source and other U.S. facilities suitable for the very complicated characterizations of alkali metal in surface islands and surface aggregates. Both U.S. and German postdoctoral associates and graduate students will be involved in the collaborative research. Transition metal clusters and aggregates exhibit a nonmetal to metal transition with increasing cluster size. Similar transitions have been observed for transition metal layers on solid surfaces. So far, the in-depth study needed to demonstrate a direct connection between metal to nonmetal transition in clusters and at surfaces has been done successfully only for one metal, mercury. These investigators propose to expand that base of knowledge by undertaking the necessary comparative research on transition in alkali metals. Since data already exist on alkali b ehavior in surface layers, the joint research will focus principally on the transition in clusters. Results from this research will contribute to understanding the basis for the difference in behavior between metals and non-metals. ***