The Self-assembled Structure Of Rubrene On The Surface Of Pb Island And The Magnetic Nano-lattice Of Co On Bi(111)

Scanning tunneling microscopy (STM) is an very important characterization technique in the nanometer science technology field. It can not only characterize the morphology of nanostructures under the atomic scale, but also can obtain the information of electronic structure, such as the material of the electron density distribution. As the function and use of the scanning tunneling microscopy (STM) increasingly expanding, it will be more widely applied in many other relevant fields. This experiment using the ultra-high vacuum low temperature scanning tunneling microscope to measure the self-assembled structures of rubrene on the surface of Pb island and the magnetic nanometer lattice of Co on the surface of Bi (111). Firstly, this thesis discussed how the Pb/Si quantum size effect results in the formation of the quantum well states; how the thickness of Pb film influence the change of the density of electronic states near the Fermi level; And principles of problems as the relationship between the adsorptivity of the surface of the Pb film and the film local work function. On the basis of above, I performed the experimental measurement and obtained different thickness electronic structure of Pb by using the STS. The second part of the experiment is on the basis of the Pb/Si system, making the rubrene molecules keep growing on the surface of the Pb island. I quantitatively studied the selective adsorptivity of the rubrene molecules on the surface of the Pb island under the modulation of the quantum size effect, and I observed that under different cover degree the rubrene molecules formed different molecular self-assembly structures on the Pb island. The third part of this thesis introduces the preparation and characterization of low dimensional magnetic nanostructures. We grew magnetic nano clusters of Co atoms on the surface of the half metal Bi (111). We found that the Co atoms preferentially adsorbed on the edge of the substrate steps, and formed nano clusters. At the low coverage, Co nano clusters along the direction of substrate steps fonned a two-dimensional array. At the high coverage, nano clusters gathered to form two-dimensional film.