摘要
用ＸＰＳ，ＵＰＳ，ＡＥＳ和功函数测量等方面研究了不同温度下氯的吸附和脱附．氯在Ｎｉ（１１０）表面是解离的化学吸附．其初始粘附几率及饱和复盖度都与吸附温度有关．氯吸附的Ｎｉ（ｌ１０）表面即使加热到７００Ｋ都不能导致氯原子向体相渗进．氯在８２３－９２３Ｋ温度范围内的等温脱附动力学是１．５级的脱附．对吸附和脱附机理进行了讨论．
Abstract The adsorption and thermal desorption of cholrine on Ni(ll0) at different tempestures have been studied with UPS, XPS, AES and work function measurements. Chlorine dissociatively adsorbs via a precursor state and remains chemisorbed on Ni(l10) surface. Sticking probability keeps essentially constant over an initially wide.coverage range. Increasing or the substrate temperature cause only a sligrt decrease in the initial sticking probability So and the saturation coverage θ. at 193-723K. However, above-800K a substantially decrease of So and θ8, occurs due to the chlorine desorption into the vacuum. Heating the chlorine adsorbed surface to-700K causes the chlorine desorption but does not lead to incorporration of chlorine atoms into the bulk, indicating a high activation enrgy of penetration for Cl atoms. The isothermal desorption of chlorine was found to follow 1 .5 order kinetics between 823 and 923K,which implies that the formation or the surface complex NiCl2(a) is the rate determing step.The influence of the surface temperature and the lateral interaction at the surface on the desorption kinetics are discussed in detail.
基金
国家自然科学基金
中国科技大学结构研究开放实验室资助
