Electronic and Optical Properties of GaAlAs/GaAs Thin Films

Technical Physics - It has been shown that the formation of GaAlAs nanofilms on a GaAs surface leads to an increase in the emission coefficient of true secondary electrons and in the quantum yield...     

On the creation of ordered nuclei by ion bombardment for obtaining nanoscale si structures on the surface of CaF<Subscript>2</Subscript> films

The effect of preliminary low-energy (~1 keV) and low-dose (~10¹²–10¹⁴ cm^–2) ion bombardment on the initial stages of growth of Si films on a CaF₂/Si surface is investigated. Ordered nanocrystal phases (thickness less than 5–6 monolayers) and homogeneous epitaxial nanofilms (thickness more than 8–10 monolayers) of silicon are shown to be formed after annealing.     

Analysis of the structure and properties of heterostructured nanofilms prepared by epitaxy and ion implantation methods

The energy band diagram of multilayer nanofilm systems formed on the basis of Si, GaAs, and CaF₂ is constructed. The optimal regimes of obtaining homogeneous films of a complex composition are determined.     

The Morphology and Electronic Properties of Si Nanoscale Structures on a CaF2 Surface

Technical Physics - The surface morphology, crystal structures, and band-energy parameters have been studied for nanofilms and regularly arranged nanoscale Si phases with a thickness of 1–2...     

Emissivity of Laser-Activated Pd–Ba Alloy

Technical Physics - Comparative analysis of the influence of temperature and laser activation on the secondary electron emission coefficient and work function (eφ) in Pd–Ba alloy (1.5 at...     

Propagation of a spherical wave in nonlinearly compressible and elastoplastic materials

The problem of spherical wave propagation in soil under the action of an intense uniformly decreasing load ₀(t) applied to the boundary of a cavity with radius r₀ is considered. Soil with a high stress level is modeled either by ideally nonlinearly compressible or elastoplastic material, taking account of linear irreversible unloading for the material. In contrast to [1–7], in order to describe material movement use is made of strain theory [8] with determining functions = (), _i=_i(_i), where , _i, , _i are the first and second invariants of strain and stress tensors. During material loading these functions are presented in the form of polynomials ()=(_i+₂¦¦), _ii)=(_i-_2i)_i, in which constant coefficients _i, _i=1, 2) are determined by experiment, taking account of the triaxial stressed state of soil. Solution of the problem is constructed by an analytically reversible method, with prescribed shape for the shock-wave (SW) surface in the form of a second-degree polynomial relating to time t and a numerical method of characteristics for a prescribed arbitrarily decreasing load _i(t). On the basis of the analytical equations obtained, calculations are carried out for material parameters (including loading profile) in a computer and stresses and mass velocity of plastic and elastoplastic materials are compared.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 4, pp. 95–100, July–August, 1986.The authors express their sincere thanks to Kh. A. Rakhmatulin for discussing the results of this work.