Atomic and Electronic Structures of a Single Oxygen Molecular Junction with Au, Ag, and Cu Electrodes

Fabrication of oxygen molecular junctions was demonstrated for a series of single metal wires of Au, Ag, and Cu using the mechanically controllable break junction method at low temperature (10 K). On the basis of conductance measurement, vibrational spectroscopy, and current–voltage (I–V) response of the molecular junctions, we provide experimental evidence that the oxygen can incorporate into the metal wires to form single oxygen molecular junctions. Conductance behavior during the elongation process of the molecular junctions revealed the formation of single one-dimensional wire. The incorporation of oxygen into the metal wires was demonstrated in vibrational spectroscopy and I–V response measurements. Furthermore, detailed analysis of the I–V response based on the single channel transport model allowed us to quantitatively evaluate electronic properties of the molecular junctions as metal–molecule electronic couplings and an energy level of a transport channel. The present study demonstrated that oxygen can interact with atomic wires of the noble metals and could provide insight into oxidation process of low-dimensional materials.