We describe an adjustable, oxide-free, tunnel junction with the stability necessary to observe the vibrational modes of molecules adsorbed on clean metal surfaces. We illustrate the capabilities of this device with inelastic tunneling data from junctions whose barriers are formed by neon/acetylene mixtures of varying concentration. From the concentration dependence of the inelastic spectra, we can distinguish between acetylene molecules chemisorbed on the metal electrodes and those that are either physisorbed or incorporated in the neon barrier.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)