U.S.-Czechoslovakia Materials Research on Diffraction Studies of Excited Electron States and of Dynamic Processes on Crystal Surfaces

劳伦斯·伯克利实验室的M.A.Van Hove博士和捷克斯洛伐克科学院物理研究所的I.Bartos博士开展的这项美国-捷克斯洛伐克研究项目将研究激发电子态的衍射和晶体表面的动态过程。研究人员将探索金属表面的动态电子过程，这与理解多体效应有关，多体效应将澄清电子在低维系统中的行为。这种非弹性效应将在低能电子的衍射中通过将模型光学势与实验数据进行拟合来研究。这些结果可能有助于揭示真空能级以上未占据态的电子结构，例如过渡金属在接近真空能级时通常的非弹性平均自由程。这项工作也应该有助于理解吸附表面的光化学动力学的寿命。另一个好处是更好地获得非常轻的元素，主要是氢，这可以导致表面重建。这些结果将对理解催化、晶体生长和纳米结构的性质具有重要意义。这一材料科学研究项目通过使美国和东欧的顶尖专家能够将互补的人才结合在一起，并在相互感兴趣和能力很强的领域汇集资源，从而实现了促进科学知识的计划目标。

This US-Czechoslovak research project between Dr. M. A. Van Hove of Lawrence Berkeley Laboratory and Dr. I. Bartos of the Institute of Physics of the Czechoslovakian Academy of Sciences will study diffraction of excited electron states and of dynamic processes on crystal surfaces. The researchers will explore the dynamic electron processes at metal surfaces, which are relevant for understanding many- body effects that will clarify the behavior of electrons in lower-dimensional systems. Such inelastic effects will be studied in the diffraction of low-energy electrons, by fitting model optical potentials to experimental data. Results may shed light on the electronic structure of unoccupied states above the vacuum level, such as the usual inelastic mean free path in transition metals at energies close to the vacuum level. The work also should benefit the understanding of lifetimes in photochemistry cynamics at surfaces with adsorbates. A further benefit would be better access to very light elements, principally hydrogen, which can induce surface reconstruction. These results would be important in understanding catalysis, crystal growth and properties of nanostructures. This research project in materials science fulfills the program objective of advancing scientific knowledge by enabling leading experts in the United States and Eastern Europe to combine complementary talents and pool resources in areas of strong mutual interest and competence.