Traeger Franziska
Lehrstuhl für Physikalische Chemie, Ruhr Universität Bochum, Universitätsstr. 150, 44801 Bochum, Germany.
Chemphyschem. 2006 May 12;7(5):1006-13. doi: 10.1002/cphc.200500599.
Many experimental methods of surface science employ electrons or photons of considerable incident energy as probe particles. However, insulating surfaces or delicate physisorbed layers may be damaged by these particles and should, therefore, be analyzed with a gentler probe: He atom scattering allows to determine the symmetry of the unit cell and the detection of phase transitions from diffraction measurements as well as the determination of surface and adsorbate vibrations by time-of-flight resolved detection. Herein, the application of He atom scattering to oxide surfaces is demonstrated on the basis of the examples of MgO and ZnO. MgO(001) is a very inert and stable surface, whereas hydrogen atoms are chemisorbed on the mixed-terminated ZnO(1010) and on both polar faces: ZnO(0001) and ZnO(0001). He atom scattering is very sensitive to the presence of hydrogen on surfaces. In addition ZnO reacts with molecules such as water, CO and CO(2). It is demonstrated that in combination with photoelectron spectroscopy and thermal desorption spectroscopy He atom scattering can also contribute to studies of surface chemistry.
表面科学的许多实验方法都采用具有相当入射能量的电子或光子作为探测粒子。然而，绝缘表面或脆弱的物理吸附层可能会被这些粒子损坏，因此，应该用更温和的探测器进行分析：氦原子散射可以通过衍射测量确定晶胞的对称性和检测相变，以及通过飞行时间分辨检测确定表面和吸附质的振动。在此，以氧化镁（MgO）和氧化锌（ZnO）为例展示了氦原子散射在氧化物表面的应用。氧化镁（001）表面非常惰性且稳定，而氢原子化学吸附在混合端接的氧化锌（1010）以及两个极性面：氧化锌（0001）和氧化锌（0001）上。氦原子散射对表面上氢的存在非常敏感。此外，氧化锌会与水、一氧化碳和二氧化碳等分子发生反应。结果表明，结合光电子能谱和热脱附能谱，氦原子散射也有助于表面化学的研究。
