Center for Functional Nanomaterials Seminar
"Oscillation of conductivity in layer-by-layer growth of Bi thin film phase"
Presented by Yasunori Fujikawa, Institute for Materials Research, Tohoku University, Sendai, Japan, Japan
Thursday, March 14, 2013, 4 pm
CFN, Building 735, Conference Room B
Hosted by: Jurek Sadowski
Thin film growth of Bi and related compounds has been attracting much attention because of their exotic properties originating in the large spin-orbit interaction of Bi. Growth of its simple substance is known to result in the formation of a thin-film phase in the initial stage, which is taken over by the bulk growth when the coverage exceeds several monolayers (ML).  With typical growth conditions, this transition takes place before the completion of the thin-film layer, which tends to agglomerate to form 4-ML thick islands, making it difficult to measure the intrinsic property of the thin-film phase. In this work, Bi growth on Si(111)-7x7 has been performed in a multi-probe VT-STM system, which provides wide-ranging opportunity of kinetic control and in-situ transport measurement during the thin film growth. By tuning the kinetic condition of the growth, it becomes possible to grow the thin-film phase uniformly covering the substrate in layer-by-layer mode. In-situ transport measurement has been performed during the layer-by-layer growth of the Bi thin-film phase, distinguishing the conductivity of each growth unit. It oscillates with a period of 2 ML, which reflects the atomic structure of the thin-film phase.  Nagao et al., Phys. Rev. Lett. 93, 105501 (2004). Host: Jurek Sadowski Joann Tesoriero Center for Functional Nanomaterials Bldg. 735 Upton, NY 11973 (631) 344-7791 fax (631) 344-3093 Tesoriero@bnl.gov