Gd-Ni界面的电子结构及其氧化现象

The Electronic Structure and Oxidation of Gd-Ni Interface

用同步辐射光电发射谱 (SRPES)和XPS研究了室温下Gd膜在Ni(1 1 0 )上的生长和Gd Ni界面的电子结构以及它们的氧化现象 .发现Gd膜在高覆盖度时Gd 4f为双峰结构 ,高温退火使 4f双峰退为单峰 .氧在 3.7nm的Gd膜上的吸附引起Gd 4f双峰中高结合能峰的衰减 ,在 0L～ 5 0L的氧暴露量范围内 ,只存在单一的晶格氧物种 .在轻微氧化的Gd Ni复合薄膜上 ,氧吸附引起Gd向表面的偏析和进一步氧化 ,并存在化学吸附氧 (O-)和晶格氧两种氧物种 .本文对Gd 4f双峰的起源 。

The growth of Gd film on Ni(110) and the electronic structure and oxidation of Gd Ni interface were studied by synchrotron radiation photoemission spectroscopy and XPS. When Gd coverage was higher than 0.22 nm, Gd 4f emission showed a double peak. Which evolved into a single peak on annealing at 600 K. Oxygen adsorption led to the attnuation of the high BE peak in the double peak of Gd 4f, concurrently, the O 1s XPS spectra exhibited only one peak attributed to lattice oxygen in the range of 0 L～50 L exposure. On the surface of the slightly oxidized Gd Ni composite film, oxygen adsorption resulted in the surface segregation and oxidation of Gd component, and two kinds of oxygen species, the chemsorbed O - ion and lattice oxygen, were detected. The origin of Gd 4f double peak and the oxidation mechanism as well as the nature of the surface oxygen species are discussed.