Low-energy electron transmission

Here we discuss the application of low energy photoelectron transmission spectroscopy (LEPS) as a means for investigating the electronic properties of OOTF. In a typical experiment photoelectrons are ejected from the conductive substrate and after being transmitted through the adsorbed layer, the energy (and or angle) dependent electrons flux is measured as a function of incident photon energy, molecular film thickness, adsorbate and substrate types and temperature. 

Li et al. made extraordinarily perfect artificial c-axis twist bicrystal junctions.[3] These junctions were extensively characterized using high resolution transmission electron microscopy (HRTEM), electron energy loss spectroscopy, and low energy electron diffraction, etc., and the results were compared with computer simulations. [4] More recently, off-axis electron holography provided compelling evidence of the remarkable atomic perfection and reproducibility of the twist junctions.[5]... 

The transmission electron microscopy was done with a 100-kV accelerating potential (Hitachi 600). Powder samples were dispersed onto a carbon film on a Cu grid for TEM examination. The surface analysis techniques used, XPS and SIMS, were described earlier (7). X-ray photoelectron spectroscopy was done with a Du Pont 650 instrument and Mg K radiation (10 kV and 30 mA). The samples were held in a cup for XPS analysis. Secondary ion mass spectrometry and depth profiling was done with a modified 3M instrument that was equipped with an Extranuclear quadrupole mass spectrometer and used 2-kV Ne ions at a current density of 0.5 /zA/cm2. A low-energy electron flood gun was employed for charge compensation on these insulating samples. The secondary ions were detected at 90° from the primary ion direction. The powder was pressed into In foil for the SIMS work. 

The methods of scanning and transmission electron microscopy are broadly used for the investigation of various objects of colloidal nature [40], It is worth mentioning here the technique of the preparation of replica of rapidly frozen sols, which allows one to freeze the system at a given moment of time. The surface structure can be effectively analyzed by such methods as Auger Electron Spectroscopy (AES), Low Energy Electron Diffraction (LEED), Secondary Ion Mass Spectroscopy (SIMS), and others. 

---