Inverse photoemission spectroscopy has been used to study the unoccupied electronic state of NbC and TiC (100) surfaces. Most of the features of the spectra are well explained by the unoccupied bulk states expected from theoretical band calculations along Γ-X direction. An unoccupied surface state is identified for the NbC (100) surface. After oxygen adsorption, empty O 2p derived states are observed for both surfaces. For the TiC (100)-O surface, IPES spectra indicate that the oxycarbide layer is formed by heating at 1000°C, which is not observed for the NbC (100)-O surface.
The silica-overlayer deposited on MgO (SiOx/MgO) is prepared by the chemical vapor deposition of tetramethoxysilane. The surface property of the resulting oxides is characterized by XPS, IR, TPD and titration techniques. The deposition of silica overlayer brings about a change in acid-base property of the surface or the concentration of surface hydroxyls. The generation of Lewis acid sites on SiOx /MgO is evidenced by 1R spectra of adsorbed pyridine. The amount and the strength of acid of SiOx /MgO are found to be greater than those of silica gel. With increasing silanization period (the amount of deposited SiOx), the amount and the strength of acid increase at coverages less than monolayer, while the multilayer deposition of SiOx layer decreases the surface acidity. XPS study shows that the chemical state of Si atoms in SiOx overlayers is different from that in silica gel. It is concluded that the generation of acid sites on SiOx/MgO results possibly from the electronic and structural effects from the MgO substrate through Mg-O-Si bond formed at the interface.
The surface structure of (NH4)2Sx-treated GaAs (100) was observed with a scanning tunneling microscope (STM) both in air and in vacuum. STM images obtained showed line shaped protrusions which run  direction and are 220 nm in width. For the sulfur treated n- and p-GaAs surfaces with 400°C-20 min heating, about 1 eV surface band bendings toward higher and lower binding energy side were observed, respectively. No band gap state appeared for either case.
The analysis of the reflection high energy electron diffraction (RHEED) patterns from the vicinal Si(111) (misoriented 1°-6° from  to ) and (100) surfaces (misoriented 0.4°-4° from  to ) clarified the differences in step structures on the two surfaces. On the vicinal Si(111) surface, wide terraces with a 7 7 structure and step bunching regions were observed; whereas on the vicinal Si (100) surface, a regular monolayer or bilayer step array was observed. Terrace width and multilayer step height on the vicinal Si (111) surface were estimated by RHEED, scanning electron microscopy, and transmission electron microscopy. The terrace width and multilayer step height were gathered as functions of misorientation angle.
An analysis of air-oxidized polyacetylene (PA) showed higher order structural changes such as expansion of fibril diameter and partial splitting of fibrils as well as the conventionally found primary structural changes caused by breakage of double bonds in the main chains into carbonyl and hydroxyl groups. These were evidently confirmed by SEM observation. Also, X-ray diffraction analysis revealed disordered crystal orientation and degenerated crystallization.