Positron Annihilation Induced Auger Electron Spectroscopy

这个实验计划将采用正电子湮没诱导 俄歇电子能谱（PAES）用于研究表面和 俄歇过程本身。 UTA磁引导PAES 系统将被用来直接识别元素的含量 最上面的原子层，并获得俄歇光谱， 极低的能量剂量率。 要研究的系统包括（1） 由以下成分组成的双金属膜的生长和相互扩散 铜上的铁、钕和钯，（2）吸附在金属上 表面，（3）合金中的表面偏析，以及（4）脆性 吸附层和化学不稳定系统，包括有机 催化表面上的分子和导电聚合物。 未来 正电子束的改进将使一种新形式的 极化俄歇光谱学在磁性研究中的应用 系统中，初始孔的极化，而不是 选择出射电子。

This experimental program will employ Positron annihilation induced Auger Electron Spectroscopy (PAES) for the study of surfaces and the Auger process itself. The exising UTA magnetically guided PAES system will be used to identify directly the elemental content of the top-most atomic layer and to obtain Auger spectra with extremely low energy dose rates. Systems to be studied include (1) the growth and interdiffusion of ultrathin metal films composed of iron, neodymium and palladium on copper, (2) adsorbates on metal surfaces, (3) suface segregation in alloys, and (4) fragile adsorbed layers and chemically unstable systems including organic molecules on catalytic surfaces and conducting polymers. Future modifications of the positron beam will make possible a new form of polarized Auger spectroscopy for use in the study of magnetic systems in which the polarization of the initial hole rather than the outgoing electron is selected.