Dynamic behavior and phase transition of magic Al clusters on Si(111)-7 X 7 surfaces

摘要

By means of high-temperature scanning tunneling microscopy, the authors present a direct observation on the dynamic behavior and phase transition of magic Al clusters on Si(111)-7 X 7 surfaces at high temperature. When the temperature is above 500 ℃, fast diffusion of magic Al clusters on Si(111)-7 X 7 surfaces occurs while the magic cluster phase transforms into √3 X √3-Al phase on downterraces (the downstep side of a terrace). From an Arrhenius plot, the activation energy of magic Al clusters on Si(111)-7 X 7 surfaces was extracted to be 2.0±0.3 eV. This study supplies important information for understanding the formation and phase transition process of magic Al nanoclusters on Si(111)-7 X 7 surfaces.