内嵌金属富勒烯Gd@C_(82)在Cu(111)和Pt(111)表面吸附结构的STM研究

STM study of adsorption structures and electronic state of endohedral metallofullerene Gd@C_(82) on Cu(111) and Pt(111)

利用扫描隧道显微镜(STM)研究分析了内嵌金属富勒烯分子Gd@C82在Cu(111)和Pt(111)上的低温(200～250 K)生长方式和吸附结构。不同强弱的分子-衬底间相互作用导致Gd@C82在Cu(111)和Pt(111)上的生长方式有很大区别。经过热处理后,Gd@C82分子诱导Cu(111)衬底发生重构,而在Pt(111)上未发现此现象。两种金属衬底不同的晶格常数和电子性质导致退火后的分子自组装结构也不一样:Gd@C82在Cu(111)上形成等价的两种吸附结构,即(√19×√19)R23.4°和(√19×√19)R36.6°;分子在Pt(111)上形成一种与〈110〉方向一致的密堆积结构。

The growth and adsorption structures of endohedral metallofullerene Gd@ Cs2 adsorbed on Cu （ 1 1 1 ） and Pt （ 111 ） at low temperature （200 -250 K） were investigated by scanning tunneling microscopy （STM）. Different molecule-substrate interactions lead to discrepant growth patterns of molecules on Cu（ 111 ） and Pt（ 111 ）. Gd@ Cs2 molecules induce Cu（ 111 ） substrate reconstruction by thermal treatment. However, this phenomenon is not observed on Pt（ 111 ）. Due to different lattice constants and electronic properties of these two substrates, the stable self-assembled structures of Gd@ Cs2 after annealing are not consistent. Two equivalent adsorption structures are formed on Cu（ 111 ）, i.e. , （ √19×√19） R23.4° and （ √19×√19） R36.6°, whereas on Pt（ 111 ） the structure with the arrangement direction consistent with the lattice of the substrate is formed.