Unisized two-dimensional platinum clusters on silicon(111)-7x7 surface observed with scanning tunneling microscope.
Unisized two-dimensional platinum clusters on silicon(111)-7x7 surface observed with scanning tunneling microscope.
复制标题
用扫描隧道显微镜观察到硅(111)-7x7表面上均匀尺寸的二维铂簇。
DOI：
10.1063/1.2018639
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
T. Kondow
中科院分区：
文献类型：
--
作者：
H. Yasumatsu;T. Hayakawa;S. Koizumi;T. Kondow
通过在室温下以每个原子1.5电子伏特的碰撞能量将尺寸选择的铂团簇离子沉积在硅（111） - 7×7表面上，制备了单尺寸的铂团簇（尺寸范围为5 - 40）。在低于5×10⁻⁹帕的环境压力下，于77 K的温度使用扫描隧道显微镜（STM）对如此制备的表面进行观测。在不同团簇尺寸下观察到的STM图像显示：（1）团簇变扁平并通过类似于硅化铂的化学键附着在表面上；（2）在团簇尺寸达到20时，每个铂原子优先占据分布在硅表面直径约2纳米范围内的最具反应性的位点，在此尺寸以上，团簇的直径随尺寸增大；（3）入射团簇离子在表面上的附着概率随团簇尺寸增大，在尺寸大于20时几乎达到1。
Uni-sized platinum clusters (size range of 5-40) on a silicon(111)-7 x 7 surface were prepared by depositing size-selected platinum cluster ions on the silicon surface at the collision energy of 1.5 eV per atom at room temperature. The surface thus prepared was observed by means of a scanning tunneling microscope (STM) at the temperature of 77 K under an ambient pressure less than 5 x 10(-9) Pa. The STM images observed at different cluster sizes revealed that (1) the clusters are flattened and stuck to the surface with a chemical-bond akin to platinum silicide, (2) every platinum atom occupies preferentially the most reactive sites distributed within a diameter of approximately 2 nm on the silicon surface at a cluster size up to 20, and above this size, the diameter of the cluster increases with the size, and (3) the sticking probability of an incoming cluster ion on the surface increases with the cluster size and reaches nearly unity at a size larger than 20.