清洁及部分氧化的Ni_3Ti(0001)表面CO吸附的HREELS研究

用离子散射谱（ＩＳＳ）、俄歇电子能谱（ＡＥＳ）及低能电子衍射（ＬＥＥＤ）技术对Ｎｉ３Ｔｉ（０００１）表面结构与组成进行考察后，主要采用高分辨电子能量损失谱（ＨＲＥＥＬＳ），以ＣＯ为探针分子，研究了清洁及部分氧化的Ｎｉ３Ｔｉ（０００１）表面上Ｎｉ，Ｔｉ间的相互作用及对ＣＯ吸附态的影响．结果表明：（１）在最表层几乎完全为Ｎｉ的Ｎｉ３Ｔｉ（０００１）清洁规整表面上，ＣＯ没有发生解离；（２）次表层Ｔｉ原子与最表层Ｎｉ原子间的电子相互作用，使初始吸附的ＣＯ伸缩振动与Ｎｉ（１１１）相比向低频位移约６０ｃｍ－１；（３）适量ＣＯ暴露后，ＣＯ氧端与近邻Ｔｉ原子的成键作用产生了一种新的Ｎｉｘ－Ｃ－Ｏ－Ｔｉｙ物种．Ｎｉ３Ｔｉ（０００１）表面部分氧化后，上述（２）和（３）作用消失

HREELS STUDY OF ADSORPTION OF CO ON CLEAN AND PARTIALLY OXIDIZED Ni 3Ti(0001

The surface composition and structure of clean and partially oxidized Ni 3Ti(0001) were examined by ion scattering spectroscopy (ISS), Auger electron spectroscopy (AES) and low energy electron diffraction (LEED). The interaction between nickel and titanium atoms on the above two surfaces and the effect of which on CO adsorption state were studied by high resolution electron energy loss spectroscopy (HREELS). The results showed: (1) no dissociation of CO on the ordered Ni 3Ti(0001) surface which is quasi pure nickel, (2) about 60 cm -1 shift of C-O stretching vibration of initially adsorbed CO to lower frequency due to a small electronic interaction of adjacent Ti atoms on Ni, (3) a new Ni x C O Ti y species resulting from the bonding interaction of the oxygen end of CO with adjacent Ti atoms. After partial oxidation, the interaction described in (2) and (3) disappeared.