In this thesis, we use the LITD/LEEM method to study the mass transport in the Pb wetting layer on the Si(111) surface. The anomalous Pb mass transport on the Si(111) surface was reported previously [K.L. Man et al., Phys. Rev. Lett. 101, 226102 (2008).]. The earlier work lacks careful coverage calibration and the information on the structural properties of the Pb α-phase film. In this thesis, we proposed a very careful coverage calibration procedure to determine the coverage of the Pb α-phase film. We also explored the structural properties of the Pb α-phase film using real time LEED measurement. Several phase transitions were confirmed in this system and a new phase diagram was constructed....[ Read more ]

In this thesis, we use the LITD/LEEM method to study the mass transport in the Pb wetting layer on the Si(111) surface. The anomalous Pb mass transport on the Si(111) surface was reported previously [K.L. Man et al., Phys. Rev. Lett. 101, 226102 (2008).]. The earlier work lacks careful coverage calibration and the information on the structural properties of the Pb α-phase film. In this thesis, we proposed a very careful coverage calibration procedure to determine the coverage of the Pb α-phase film. We also explored the structural properties of the Pb α-phase film using real time LEED measurement. Several phase transitions were confirmed in this system and a new phase diagram was constructed.

With the knowledge of film coverage and structural properties, we use the LITD/LEEM method to study the non-equilibrium profile evolution in the Pb wetting layer on the Si(111) surface in greater detail than previously, including its coverage dependence and temperature dependence. The critical coverage in mass transport behaviour is confirmed and assigned to a new value using the new careful coverage calibration methods. The coverage dependence of equilibration time was also correlated with LEED measurements, and coverage dependent activation energies were determined.