摘要:

A review of the basic concepts of the interaction between slow electrons with energies between 10 and103 eVand surfaces is presented. First, the solid is considered to consist of an electron gas with a charge compensating, spatially constant positive background (jellium) or of an assembly of completely randomly distributed atoms with truncated potentials (randium). Next the influence of the periodic nature of the solid on the interaction process is taken into account (diffraction). Finally, the effects associated specifically with the presence of the surface are discussed.

ISSN:0022-5355    

DOI:10.1116/1.1315823

出版商:American Vacuum Society    

年代:1970

数据来源: AIP

ISSN:0022-5355    

DOI:10.1116/1.1315771

出版商:American Vacuum Society    

年代:1970

数据来源: AIP

摘要:

Quantitative oxygen coverage as a function of oxygen exposure has been determined in an Auger electron spectroscopy study of oxygen adsorption on W(110). The oxygen Auger peak of the secondary electron energy distribution was resolved from the background, and the area of the peak was taken as proportional to the oxygen coverage. The initial slope of the coverage vs exposure curve provided a value of 0.23 ± 0.05 for the initial sticking coefficient. Comparison of the results with other studies is presented.

ISSN:0022-5355    

DOI:10.1116/1.1315780

出版商:American Vacuum Society    

年代:1970

数据来源: AIP

摘要:

Noble gas ions in the energy range 100–2400 eV have been trapped in single crystal and in polycrystalline nickel targets. The thermal release spectra of these gases have been studied as a function of dosage, temperature, and pretreatment. Measurement of thermal release rates yield maxima from which critical activation energies can be deduced. Most of these activation energies appear to be characteristic of the metal bombarded. Activation energies obtained from these studies are compared with those for thermally activated processes in the bulk metal.

ISSN:0022-5355    

DOI:10.1116/1.1315791

出版商:American Vacuum Society    

年代:1970

数据来源: AIP

摘要:

Historical highlights of studies of current flow across metal-semiconductor contacts via electron tunneling are outlined. The physical origin of the space-charge potential at a rectifying metal contact on a degenerate semiconductor is illustrated with emphasis on the features of this potential which determine the dominant mechanism of current flow across the contact. Recent experiments on the tunneling characteristics of these junctions are described. Their interpretation in terms of phenomenological independent-electron models is discussed critically. The tunneling spectroscopy of collective excitations is described by use of the transfer-Hamiltonian model. The influence of features of the phonon spectra in the semiconductor on inelastic tunneling is illustrated for Ge. The effects of electronic interactions with collective excitations in the semiconductor electrode are discussed for phonons in Si and CdS, and for plasmons in GaAs. The references given herein supplement those presented in a recent comprehensive review.

ISSN:0022-5355    

DOI:10.1116/1.1315804

出版商:American Vacuum Society    

年代:1970

数据来源: AIP

摘要:

This paper discusses in some detail the application of quantum scattering theory to the problem of Auger neutralization of ions at a solid surface. The formalism for rearrangement collisions in the distorted wave Born approximation has been used to calculate the secondary electron distribution and the total yield for the case ofHe+on W. The distortion of the ion and atom motion by the solid is shown to play an important role in the neutralization process. This effect accounts for the observed broadening and shift in the secondary electron energy distribution. Additional points discussed include effects of inelastic projectile scattering, changes of the energy levels in the system during the neutralization process, and the probable effect of inelastic electron interactions.

ISSN:0022-5355    

DOI:10.1116/1.1315819

出版商:American Vacuum Society    

年代:1970

数据来源: AIP

摘要:

When an energetic ion collides with the surface of a solid, it experiences forces of interaction with atoms of the solid, which condition its trajectory. There will be a certain probability, for any ion type and energy and target atom species and geometry (i.e., crystal orientation and type), that the ion will be so deflected as to be reflected from the solid surface, while there will be another probability for the ion to penetrate beyond the surface into the solid lattice. After the ion has entered a lattice, it will collide with atoms, thereby losing energy and causing atomic displacement and defect creation and if the ion is not backscattered out of the target during its slowing down or diffuses out subsequently it will eventually be entrapped at some center in the lattice. Subsequent thermal treatment can give information on the nature of these centers by studying atom motion and release into the gas phase. It is, therefore, clear that experimental measurements of reflection, penetration, and entrapment can give information on interatomic forces and dissolution processes and defect formation and the present review summarizes available theoretical and experimental data in these fields.

ISSN:0022-5355    

DOI:10.1116/1.1315821

出版商:American Vacuum Society    

年代:1970

数据来源: AIP

摘要:

An experimental technique is described for observing the adsorption of oxygen on the surface of a silicon crystal. It is shown that the current flowing in a reverse biasedp-njunction is closely related to the adsorption of oxygen. Observation of this current is used to indicate that sorption obeys first order reaction laws with an initial sticking coefficient of the oxygen on silicon of10−3.

ISSN:0022-5355    

DOI:10.1116/1.1315822

出版商:American Vacuum Society    

年代:1970

数据来源: AIP

ISSN:0022-5355    

DOI:10.1116/1.1315824

出版商:American Vacuum Society    

年代:1970

数据来源: AIP

摘要:

Auger electron spectroscopy has been used in this study to determine common impurities found on the transition metals Sc, Ti, V, Cr, Fe, Co, Ni, Y, Zr, Nb, Mo, Ru, Rh, La, Hf, Ta, W, Re, Ir, Pt, and Au. Single crystal and polycrystal specimens were used, with both specimen types giving similar results. The most prevalent impurity on most of these surfaces is not carbon as had been previously supposed but rather is sulfur. Mild heat treatment causes sulfur to segregate at the surfaces of these materials, while more drastic heating, to 1000 °C or greater, will normally remove all the sulfur. Clean Mo surfaces exhibit a peak in the Auger spectrum at 150 V, the location of the sulfur peak, but arguments are given to suggest that this peak is characteristic of the clean rather than the contaminated surface. Observations of chemical shifts in Auger spectra have been made and are also discussed.

ISSN:0022-5355    

DOI:10.1116/1.1315825

出版商:American Vacuum Society    

年代:1970

数据来源: AIP