Kinetics of Ordering for Surface Phase Transitions

Unertl教授和梁博士，埃克森公司，将利用放牧 入射X射线散射、低能电子衍射和 扫描隧道显微镜，以确定动力学 表面相变的有序化。 测量结果将是 与最近的理论预测相比， 形成和普遍的缩放行为，包括;描述 域增长，普遍性类的存在和 散射函数的标度性质， 基态简并和对称性的影响，以及 表面缺陷造成的限制。 如果验证这些 预测将允许大范围的成核和生长 不同系统中的现象可以简单地描述。 工艺过程包括烧结成膜， 激光熔化后的固化，以及 可以更好地理解快速淬火的无定形材料。 研究的模型体系包括Au（110），Pb/Cu（110）， Pb/Cu（001）和Se/Ni（001）。 实验将包括使用 布鲁克海文国家大学的国家同步加速器光源 实验室

Professor Unertl and Dr. Liang, Exxon Corp., will use grazing incidence x-ray scattering, low energy election diffraction and scanning tunneling microscopy to determine the kinetics of ordering for surface phase transitions. The measurements will be compared with recent theoretical predictions about pattern formation and universal scaling behavior including; a description of domain growth, the existence of universality classes and the scaling properties of scattering functions, the description of effects of ground state degeneracy and symmetry, and the limitations imposed by surface imperfections. If validated these predictions will permit a wide range of nucleation and growth phenomena in diverse systems to be characterized simply. Technological processes including sintering in then films, solidification following laser melting, and the stability of rapidly quenched amorphous materials can be better understood. The model systems to be studied include Au(110), Pb/Cu(110), Pb/Cu(001), and Se/Ni(001). Experiments will include the use of the National Synchrotron Light Source at Brookhaven National Laboratory.