X-ray radiography of aluminum cathodes eroded in high-current vacuum arcs

The aim of the study presented in this paper was to characterize quantitatively the erosion of aluminum cathodes in high-current vacuum arcs. The experimental setup comprised two current generators. The first one, capable of generating a current of amplitude up to 350 kA, was used to produce a plasma jet, that is, the object to be investigated. The second generator was used to produce a source of probe radiation for imaging the object under investigation in soft x rays of energy ?ν ≈ 0.5–3 keV. The findings of the study are based on experimental data obtained by electrophysical and radiographic methods. It has been shown that the cathode erosion rate in a high-current vacuum arc is a function of the charge passed through the cathode.     

Ag-induced atomic structures on the Si(110) surface

We report the results of STM investigation of the initial stage of Ag adsorption on an Si(110) surface. At 0.21 ML Ag coverage, the size and orientation of the unit cell correspond to the parameters of a 16 × 2 unit cell of clean Si(110) surface. With increasing of the Ag coverage up to 0.42 ML, the type of surface reconstruction changes to a 4 × 1-Si(110)-Ag structure. The text was submitted by the authors in English.     

Sorption–Atomic Absorption Determination of Trace Elements in Natural Waters with Dynamic Preconcentration in Electrothermal Atomizers

A sorption–atomic absorption method was proposed for the determination of ultratrace amounts of suspended and soluble forms of Ag, Cd, Bi, Pb, and Tl in natural waters using a dynamic preconcentration of these forms (separately or simultaneously) on the DETATA sorbent placed in a crucible atomizer and the subsequent direct atomic absorption analysis of the concentrate. This method is characterized by high a sensitivity and provides for the determination of elements in small volumes of unique samples. The accuracy of the determination of element species was verified by different methods in the analysis of sea and river water, atmospheric precipitation, and suspensions.     

Resonance charge relaxation in physical barrier layers

It is shown experimentally that the space charge domain (SCD) of a MIS structure can be described as a layer-macrorelaxer by applying the appropriate formula for the Schottky barrier. The maximal time of the transient t_C (the saturation time t_CH) of the change in MIS-structure capacitance upon imposition of a sufficiently large rectangular depleting voltage pulse is expressed by the formula mentioned. A new method is correspondingly proposed for determining the ionization energy of bulk centers responsible for this relaxation. A comparison with data in the literature is presented and the prospects for developing representations on resonance charge relaxation in barrier layers is indicated.     

Production and study of local inhomogeneities in semiconducting oxides

An electric-transport method is described for introducing impurities into semiconducting oxides. Local inhomogeneities may be produced in the samples in this process. Certain physical properties of the samples may be changed by electric transport.Translated from Izvestiya VUZ. Fizika, No. 2, pp. 16–18, February, 1970.     

Metallic glass electronic structure peculiarities revealed by UHV STM/STS

We present the results of ultrahigh vacuum scanning tunneling microscopy/spectroscopy investigation of metallic glass surface. The topography and electronic structure of Ni_63.5Nb_36.5 have been studied. A great number of clusters with size about 5–10 nm have been found on constant current scanning tunneling microscopy images. The tunneling spectra of normalized tunneling conductivity revealed the energy pseudogap in the vicinity of Fermi energy. For energy values above 0.1 eV the normalized tunneling conductivity changes linearly with increasing of tunneling bias. The obtained results can be understood within suggested theoretical model based on the interplay of elastic electron scattering on random defects and weak intra-cluster Coulomb interaction. The effects of the finite edges of electron spectrum of each cluster have to be taken into account to explain the experimental data. The tunneling conductivity behavior and peculiarities in current images of individual clusters can also be qualitatively analyzed in the framework of suggested model.