Abstract
We have demonstrated the potentials of a field emission scanning tunneling microscope (FE-STM), in which the STM tip can be operated as a stable field electron emission gun. The tips were treated by a thermal-field (T-F) method for remolding and cleaning. A well-controlled T-F treated tip can determine the electric field between tip and sample in the STM as a geometrical boundary condition. Using the treated tip the electron standing waves excited in a vacuum gap between tip and sample were analyzed, and the electric field near sample surfaces was evaluated by assuming a simple potential model. Furthermore, by irradiating sample surfaces with a high-energy electron beam emitted from the tip, we obtained electron energy loss spectra (EELS) and Auger electron spectra from semiconductors, HOPG and metals.
