[26a-E105-1~11] 6.6 Probe Microscopy

▲ [26a-E105-4] Atomic structure and electron distribution of ring-like Co cluster on Si (111) surface
by NC-AFM/KPFM at 78 K

〇ZHANG QU¹, Jiuyan Wei¹, Xiaopeng Liu¹, Yasuhiro Sugawara¹, Yanjun Li¹ (1.Osaka Univ.)

Keywords:nanocluster, AFM, KPFM

The Co atom adsorbed on Si (111)-7×7 surface has been investigated by NC-AFM/KPFM at 78 K. The Co atoms in the initial adsorption could be distinguished from defects on the surface by line profile and force spectroscopy. For the first time, the Co cluster and its V_LCPD image were observed by NC-AFM/KPFM. The Co cluster was shown as ring-like clusterstructure after annealing sample at 230℃, bond energy of it was weaker than Si adatom due to passivated dangling bond state. We have proposed a structure model to explain the atomic structure including with three substituted Co atoms and six liberated Si atoms. The DFT calculations with GGA mode were used to optimize the model and to simulate the KPFM image.