ELECTROLYTIC SCANNING TUNNELING MICROSCOPY AND POINT CONTACT STUDIES AT ELECTROCHEMICALLY POLISHED AU(111) SUBSTRATES WITH AND WITHOUT PB ADSORBATES

被引:60
作者
BINGGELI, M [1 ]
CARNAL, D [1 ]
NYFFENEGGER, R [1 ]
SIEGENTHALER, H [1 ]
CHRISTOPH, R [1 ]
ROHRER, H [1 ]
机构
[1] IBM CORP,DIV RES,ZURICH RES LAB,CH-8803 RUSCHLIKON,SWITZERLAND
来源
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B | 1991年 / 9卷 / 04期
关键词
D O I
10.1116/1.585393
中图分类号
TM [电工技术]; TN [电子技术、通信技术];
学科分类号
0808 ; 0809 ;
摘要
Electrochemically polished Au(111) substrates have been investigated by scanning tunneling microscopy in 0.5M NaClO4 in absence and presence of Pb underpotential adsorbates. The nm-scale morphology of the electropolished electrodes features densely terraced dome-shaped domains with heights up to more than 5 nm, whereas only small atomically flat surface regions of approximately 5 nm width are observed. During polarization in the ideally polarizable potential range in absence of Pb adsorbates, considerable smoothening and lateral displacement of the dome-shaped domains occurs within a time scale of minutes. Extended polarization in presence of a full Pb adsorbate coverage leads to a marked increase in substrate corrugation, up to the scale of several nm. At Pb-free substrates, controlled variations of the tip-sample separation in the transition regime from tunneling to point contact exhibit a similar distance dependence of the tip current as observed in previous vacuum studies, and allow for the first time an approximate assessment of the tunneling distance range in an electrolytic system. In the case of Au tips, the transition from tunneling to point contact is observed at tunneling resistances of approximately 2 x 10(4)-OMEGA, in good agreement with previous vacuum results. A tunneling regime with R(T) < 10(7)-OMEGA is assigned approximately to a substrate-tip separation range < 1 nm.
引用
收藏
页码:1985 / 1992
页数:8
相关论文
共 35 条
  • [1] OPTICAL AND ELECTROCHEMICAL STUDIES OF UNDERPOTENTIAL DEPOSITION OF LEAD ON GOLD EVAPORATED AND SINGLE-CRYSTALS ELECTRODES
    ADZIC, R
    YEAGER, E
    CAHAN, BD
    [J]. JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 1974, 121 (04) : 474 - 484
  • [2] BEHM RJ, COMMUNICATION
  • [3] BINGGELI M, UNPUB
  • [4] INSITU SCANNING TUNNELING MICROSCOPY AT POTENTIAL CONTROLLED AG(100) SUBSTRATES
    CHRISTOPH, R
    SIEGENTHALER, H
    ROHRER, H
    WIESE, H
    [J]. ELECTROCHIMICA ACTA, 1989, 34 (08) : 1011 - 1022
  • [5] CHRISTOPH R, 1989, THESIS BERN
  • [6] DURIG U, 1989, IBM RZ1879 RES REP
  • [7] UNDERPOTENTIAL DEPOSITION OF LEAD ON POLYCRYSTALLINE AND SINGLE-CRYSTAL GOLD SURFACES .2. KINETICS
    ENGELSMANN, K
    LORENZ, WJ
    SCHMIDT, E
    [J]. JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 1980, 114 (01): : 11 - 24
  • [8] GERBER C, COMMUNICATION
  • [9] INSITU SCANNING TUNNELING MICROSCOPY OF THE ANODIC-OXIDATION OF HIGHLY ORIENTED PYROLYTIC-GRAPHITE SURFACES
    GEWIRTH, AA
    BARD, AJ
    [J]. JOURNAL OF PHYSICAL CHEMISTRY, 1988, 92 (20) : 5563 - 5566
  • [10] TRANSITION FROM THE TUNNELING REGIME TO POINT CONTACT STUDIED USING SCANNING TUNNELING MICROSCOPY
    GIMZEWSKI, JK
    MOLLER, R
    [J]. PHYSICAL REVIEW B, 1987, 36 (02): : 1284 - 1287