Isaak Konstantinovich Kikoin (Obituary)

A theoretical study of grazing incidence diffraction by laterally patterned epitaxial nanostructures is presented and successfully applied to experimental findings of pseudomorphic multilayer gratings. Numerical results from a distorted wave Born approximation are given. The grating structure generates a fine structure around the reciprocal lattice points consisting of grating truncation rods, which are similar to the crystal truncation rod of a planar crystal surface. We show the influence of the grating shape, the compositional profile and the lattice strain on the intensity pattern along the grating truncation rods. The effect of lattice strain will be discussed by comparing the fully strained state (tetragonal lattice distortion), uniform strain relaxation and graduated strain relaxation in the surface grating. Our theoretical treatment allows us to interpret grazing incidence diffraction measurements obtained from strained layer gratings and superlattice gratings.

Section: Introductionmentioning

confidence: 99%

Grazing incidence diffraction by laterally patterned semiconductor nanostructures

Baumbach

Lübbert

1999

“…A few words about the role of negative ions in formation of the reactive species in the discharge zone: high gas temperature (T ≈ 950 K) in this zone leads to the rate of electron detachment from negative ions practically overcoming the rate of electron attachment to oxygen [54], and the role of negative ions in the charged particle kinetics being negligible. In other words, the main role in the generation and excitation of reactive species in the discharge zone belongs to electrons.…”

Section: Composition Of Reactive Species In the Discharge Zone And Pl...mentioning

confidence: 99%

On the composition of reactive species in air plasma jets and their influence on the adhesion of polyurethane foam to low-pressure polyethylene

Akishev¹,

Aponin²,

Petryakov³

et al. 2018

In this paper, non-thermal plasma sources based on the high-frequency sinusoidal coaxial dielectric barrier discharge (DBD) using fast flowing ambient air as feedstock gas at atmospheric pressure are described. These single- and multi-tube sources are able to generate low- and high-power turbulent plasma jets. Experimental results on both the spatio-temporal behavior of plasma inside the DBD and parameters of plasma jet(s) outside the discharge zone are presented. These results are complemented by information on the composition of reactive species generated by high-power airflow DBD. This information has been obtained from analysis of the emissive spectra of the discharge zone and plasma jet in the UV–visual region. The basic set of elementary plasma-chemical processes responsible for the generation of reactive species in the discharge zone and their further changes in hot air plasma jet is also presented. Although the oxygen concentration in the working gas is high, the concentration of reactive species in the plasma jet is enough for effective surface treatment. This is proved by the essential improvement in the adhesion of polyurethane foam (PF) to low-pressure polyethylene (PE) after treatment by the hot air plasma jet. The changes in the spatial microstructure of the scaffolds on PE surfaces taking place after plasma treatment have been established. The reasons for the adhesion improvement are discussed. The results obtained are of both scientific and practical interest, since PE pipes covered with PF are used in the housing and community sectors, the oil and gas industry, etc.

“…Collisions between active particles and negative ions result in fast electron detachment in air (Kossyi et al 1992). Another way of increasing the rate of electron detachment in air is to heat the gas to ∼ 1000 K. This leads to fast electron detachment from the O − 2 ion (Massey 1976, Aleksandrov 1986.…”

Section: The Effect Of Electron Pseudo Diffusion On Rf Breakdown In R...mentioning

confidence: 99%

High-frequency electrical breakdown in electronegative gases with fast electron attachment and detachment processes

Aleksandrov¹,

Napartovich²,

Okhrimovskyy³

1997

Department of Physical Mechanics, Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia Troitsk Institute for Innovation and Fusion Research, 142092 Troitsk, Moscow Region, Russia Received 1 April 1996 Abstract: Breakdown in a high-frequency uniform electric field in electronegative gases with fast electron attachment and detachment processes is theoretically studied. A process of electron pseudo diffusion introduced earlier by Aints et al is analysed, and a breakdown criterion is regularly derived using the great difference in rate scales for collisional processes. The criterion is generalized to account for an arbitrary number of negative ion species including those which are not involved in electron detachment reactions. The importance of the electron pseudo diffusion is illustrated for specified gases (air, , etc). It is argued that the application of the concept of pseudo diffusion to the breakdown in air under the conditions of the experiment conducted previously by Aints et al is invalid.