非弾性電子トンネル分光法による金属薄膜における分子の浸透に関する研究

抄録

Studies on penetration of sample molecules (infusion doping) through metal-top electrodes of tunneling junctions of metal/insulator/metal by inelastic electron tunneling spectroscopy (IETS) were reviewed. IETS gives a detailed vibrational spectrum of adsorbed species on the insulator of the junction. It was found that water molecules penetrate the metal-top films (Au or Pb) along grain boundaries and reach the insulator surfaces, which result in the changes of the interface properties. Sample molecules were found to penetrate the metal films together with water molecules and are adsorbed on the insulator surfaces of the junctions. Tunneling spectra by penetrated molecules are identical to those obtained by doping from the vapors or solutions. Changes of junction resistances and those in the morphology of the lead-top films by infusion doping were also observed.