Laser Melting Steam Nanostructured And Scanning Probe Microscopy

The preparation and characterizations of the nanostructures are always the main work of nanoscience and nanotechnology. And a family of Scanning Probe Microscopes afford powerful implements for nanoscience and nanotechnology. It is widely accepted that scanning probe microscopes heralded the emergence of nanoscience and nanotechnology.As a excellent preparation technique for films and nanostructures, the laser ablation technique attaches more and more interest because its wide applications in scientific research field and industry.In our work, we employed scanning probe microscopes, including STM and AFM, to study the surface morphologies and transport properties of the nanostructures prepared using laser ablation technique. We will expatiate our work as following.In Chapter 1, we firstly introduced the techniques for nanostrucure fabrications and the development of scanning probe microscopy simply. Then we overviewed the evolutions in the researches of TiO₂ and TiSi₂, educing our aim of the thesis.In Chapter 2, we simply introduced the constructions of the ultra-high vacuum system and the VT STM system, and the main amelioration on the compound instruments. It is the preparing stage for our work.In Chapter 3, we present the preparation of C54 TiSi₂ nanoislands on Si(111) via high temperature annealing the TiO₂ thin films deposited by pulsed laser ablation. After being annealed at 850℃ for about 4 h, the C54 TiSi₂ nanoislands formed on the Si(111)7×7 surface. The surface morphologies and the current-voltage characteristics of the as-deposited sample and the annealed sample were studied using a homemade scanning tunnelling microscope. The X-ray diffraction patterns and the X-ray photoelectron spectroscopy spectra indicate that the nanoscaled islands are in C54-TiSi2 phase. The formation of the nanoislands is assigned to the reaction between the titanium oxide and the Si(111) substrate at 850℃ and the symmetry of the substrates. Then we discussed the transformation of the contact mode between the...