IOP Publishing, New Journal of Physics, 6(10), p. 065018, 2008
DOI: 10.1088/1367-2630/10/6/065018
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We study the electrical conductance of octanedithiol molecular junctions using a mechanically controllable break-junction setup. The stability of the system allows control of whether the electrodes get into contact before each new molecular junction formation or not (contact and non-contact modes). We find three characteristic conductance values for octanedithiol. Well-defined peaks in the conductance histograms at multiples of 1.2×10−5 G0 suggest that this value corresponds to the conductance of a single molecular junction conductance. Reproducible features are also observed at 4.5×10−5 and 2.3×10−4 G0. The first value has the strongest statistical weight, whereas the second is only observed in the non-contact mode. We propose that these two values reflect the formation of several molecular junctions in parallel between the electrodes.