Study on the atomic configuration for low-energy electron diffraction analysis on ZrO/W(100)

The ZrO/W(100) surface has remarkably low work function, and shows a peculi ar c(4X2) low-energy electron diffraction (LEED) pattern. The I-V (intensit y versus voltage) method is adopted to analyze the LEED pattern as widely u sed. The direction of Zr-O dipole has been expected vertical to the surface , because the vertical dipole most effectively reduces the surface potentia l. However, the analysis says that atomic arrangement including only the ve rtical dipole is not good enough for getting the highly reliable I-V curve, thus, horizontal dipole must be considered. (C) 2001 American Vacuum Socie ty.