Showing papers on "Scanning tunneling spectroscopy published in 1981"

Fowler‐Nordheim electron tunneling in thin Si‐SiO2‐Al structures

Abstract: The Fowler‐Nordheim tunneling of electrons from <100≳‐oriented Si into thermally grown SiO2 has been studied. The effects of the Si band structure and the accumulation layer have been carefully considered. Classical image barrier lowering has also been analyzed. The agreement between the theory and the experimental results is excellent over a large range of tunneling current. The study enables a consistent treatment of various tunneling problems where a more simplified analysis is not adequate.

Tunneling Spectroscopy for the Study of Adsorption and Reaction on Model Catalysts.

Abstract: Inelastic electron tunneling spectroscopy measures the vibrational modes of a small quantity of molecules that are included in or near the insulating layer of a metal-insulator-metal tunnel junction [l, 21. Figure 1 stows two metal electrodes separted by a thin insulating layer. If this layer is thin enough (of order 20 A) and if a voltage V is applied between the two electrodes, an electron current will flow from one electrode to the other. The maximum energy of the tunneling electrons will be of order eV. If there is a molecule in or near the insulating layer with a characteristic vibrational mode energy hv, this vibrational mode may or may not be excited by the tunneling electron. The most important factor turns out to be simply, does the tunneling electron have enough energy? In particular, is eV  hv?

Tunneling spectroscopy on the superconducting Chevrel-phase compounds Cu 1.8 Mo 6 S 8 and PbMo 6 S 8

Abstract: The Chevrel-phase compounds PbMo6S8 and Cu1.8Mo6S8 have been investigated by tunneling spectroscopy. These superconductors show a very strong electron-phonon interaction expressed by 4≤2δ0/kT c≤5. Structures in the tunneling density of states have been observed at most energies where the phonon spectra show maxima. The coupling of high-energy modes of the Mo6S8 units and of modes associated with displacements of the Pb (Cu) atoms are discussed.

Excitation of molecules in inelastic electron tunneling spectroscopy

Abstract: Inelastic Electron Tunneling Spectroscopy (IETS) is used for the investigation of vibronic and electronic excitations of molecules deposited as interlayers in aluminum/ alumina/lead tunneling junctions. In this review the method itself is briefly discussed. As examples, investigations by IETS on sublimated merocyanine and phthalocyanine dye molecules are reviewed. Then further doping techniques developed by Jaklevic and Gaerttner and applications of IETS to problems in the physics of interfaces are discussed.

Tunneling in the case of an energy dependent density of states

Abstract: We have solved a generalized set of three coupled Eliashberg gap equations which incorporate the effect of an energy-dependent electronic density of states N(ϵ). The model used for N(ϵ) was chosen on the basis of recent band structure calculations and the electron-phonon spectral density taken from tunneling results in Nb3Sn. The solutions are used to study of the effect of N(ϵ) on single particle tunneling into a superconductor. The theoretical characteristics so obtained are “inverted” in the conventional way and the procedure is critically assessed.

Electron tunneling in ErRh4B4

Abstract: Thin film tunneling junctions of ErRh 4 B 4 with counterelectrodes of Mg, In, Pb and Al have been formed using an artifical barrier of oxidized Er. Measurements of the tunneling characteristics indicate that the maximum value of 2Δ k B T c for ErRh 4 B 4 is at least 4.2.