半金属表面上酞菁锰分子的转动态研究

Scanning tunneling microscopy study of single rotational Mn Pc on Bi(111) surface

利用低温STM研究了半金属Bi(111)表面上单个酞菁锰分子的转动态。通过高分辨STM图发现,在液氮温度(77K)下单个酞菁锰分子呈六角形。利用STM操纵技术实现了对单个酞菁锰分子的制动,并通过对单分子的高低起伏和吸附构型分析,确定分子在Bi(111)表面做非连续的中心转动。这种单分子转动是三种相对稳定的吸附构型交替变化的结果。结合I-t谱技术,进一步验证了这三种分子吸附构型的存在;并利用近似统计分析方法得到三种吸附构型各自出现的概率以及其相对能量。

The rotational state of single manganese phthalocyanine （MnPc） molecule on Bi（111） surface was investigated using low temperature scanning tunneling microscopy （ LT-STM ） . Single MnPc molecule exhibits as a hexagon at 77 K. By means of STM manipulation technique, single molecular rotor has been blocked successfully. The height profile lines of molecules and molecular configurations on Bi （ 111 ） suface results show that single flat molecule rotates discontinuously with central axis, and it takes the rotational way that the molecule hops between three different molecular adsorption configurations. Combining the I-t spectrum, three distinct current levels has been clearly revealed due to three inequivalent configurations of molecule with respect to the tip, which further verifies the existence of three kinds of molecular adsorption configurations. Moreover, we obtained the occupation probabilities of different configurations and their related energies by approximate statistical analysis technique.