Madey T E
Science. 1986 Oct 17;234(4774):316-22. doi: 10.1126/science.234.4774.316.
Techniques for analyzing the structure and composition of solid surfaces with electron and photon beams often cause radiation damage in samples. Damage-producing processes compete with information-producing events during measurements, and beam damage can be a serious perturbation in quantitative surface analysis. There are, however, substantial benefits of electron- and photonstimulated damage processes for studying molecules adsorbed on surfaces. Direct information about the geometric structure of surface molecules can be obtained from measurements of the angular distributions of ions released by electron- or photon-stimulated desorption. The directions of ion emission are determined by the orientation of the surface bonds that are ruptured by beam irradiation. Moreover, photon-stimulated desorption studies that make use of synchrotron radiation reveal the fundamental electronic excitations that lead to bondbreaking processes at surfaces. These measurements provide new insights into radiation-damage processes in areas as diverse as x-ray optics and semiconductor electronics.
利用电子束和光子束分析固体表面结构与成分的技术常常会对样品造成辐射损伤。在测量过程中，产生损伤的过程与产生信息的事件相互竞争，并且束流损伤可能会对定量表面分析造成严重干扰。然而，电子和光子激发的损伤过程对于研究吸附在表面的分子具有诸多显著益处。通过测量电子或光子激发解吸释放的离子的角分布，可以获得有关表面分子几何结构的直接信息。离子发射方向由束流辐照导致断裂的表面键的取向决定。此外，利用同步辐射的光子激发解吸研究揭示了导致表面键断裂过程的基本电子激发。这些测量为X射线光学和半导体电子学等不同领域的辐射损伤过程提供了新的见解。
