In situ observation of change in surface atomic arrangement of Sc–O∕W(100) system during phase transition at high temperature

Abstract

In situ observation of low-energy electron diffraction (LEED) patterns during the phase transition of the Sc–O∕W(100) surface at high temperature was performed to investigate the correlation between the surface atomic arrangement, coverage of surface atoms, and work function during the phase transition. For this purpose, a LEED system enabling LEED observation at high temperatures of 1500–1900K was developed. The temperature dependence of the intensity of diffraction spots was measured, and the Debye temperatures were estimated for relevant surfaces. The changes in the intensity of diffraction spots during the phase transition were found to correlate with the changes in the coverage of surface atoms and work function. The present results revealed that surface phenomena such as surface segregation, oxidation, oxygen desorption, and diffusion of ScO complexes predominate the surface properties of the Sc–O∕W(100) system.