摘要
应用低能电子显微术对Ｗ（１１０）面二维氧化结构进行了初步研究．随着氧暴露量的增加，低能电子衍射图样由清洁表面（１×１）结构转变成ｐ（２×１），再变为带有复杂衍射卫星点的ｐ（２×２）结构．利用低能电子显微术的暗场像模式，对（００）束附近的分数衍射斑点进行了放大成像，发现表面由两种对比度相差很大的区域组成，它们就是具有不同方位取向的氧超结构畴区．两种畴区的分布与衬底表面缺陷特别是表面台阶有一定的关系。
With increasing coverage,the adsorption of oxygen on W(110) surface can be subdivided into chemisorption,two dimensional oxidation and bulk oxidation. In this work,the new imaging technique low energy electron microscopy (LEEM) was used to investigate the two dimensional oxidation on W(110) surface. With increasing O coverage,the low energy electron diffraction patterns change from (1×1) to p(2×1) structure,and then into p(2×2) with complex diffraction satellites. Using dark field LEEM mode,we have imaged the fractional spots near (00) beam. It was found that there were two kinds of regions with opposite contrast on the surface,i.e. the oxygen superstructure domains with different orientations. The distribution of these domains was related to surface defects,especially to surface steps. It was also indicated that the temperature played a very important role for surface oxidation.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
1997年第6期1048-1054,共7页
Acta Physica Sinica
