Deposition and properties of epitaxial ZnxCd1−xS ON GaAs

We describe a method for growing epitaxial layers of zinc sulfide and cadmium sulfide solid solutions on the A-side of GaAs (111) by means of separated sulfide sources in an open hydrogen iodide system. The effects of substrate temperature, amount of doping from substrate elements, and source temperatures on photoluminescence from epitaxial films of Zn_xCd_1–xS on GaAs are determined. By varying the growth conditions it is possible to primarily obtain a single band in the emission spectrum. The presence of a larger number of photoluminescence bands indicates that the solid solution is nonhomogeneous. The composition of the solid-solution films was determined through empirical relationships based on spectra from standard solutions. X-ray analysis was used to confirm the compositions.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 10–13, February, 1982.     

Growth and properties of ZnMoO<Subscript>4</Subscript> single crystals

The crystallization conditions for obtaining zinc molybdate single crystals by the Czochralski and Kyropoulos methods from a melt have been studied. The growth parameters of large single crystals of optical quality are determined. The physicochemical and spectral-luminescent characteristics of the single crystals are studied.     

Luminescence peculiarities and optical properties of MgMoO<Subscript>4</Subscript> and MgMoO<Subscript>4</Subscript>:Yb crystals

Magnesium molybdate is considered as a promising material for cryogenic scintillation bolometers. The luminescence properties of MgMoO⁴ have been investigated on single crystals grown from melts of stoichiometric and nonstoichiometric compositions and on crystals doped with Yb³⁺ ions. Their optical properties are interpreted taking into account the anisotropy of the MgMoO⁴ crystal structure.     

Creation of microdomains in an atomic force microscope in strontium-barium niobate ferroelectric crystals

Microdomains in SBN-0.61 polydomain crystals have been recorded by the atomic force microscopy method with the application of a dc voltage of 1–10 V applied to a probe. The domain areas have been obtained as functions of the voltage and exposition time. The kinetics of the decay of the domains after the shutdown of the field have been determined. The nonclassical characteristics observed in the dynamics of domain walls are attributed to the nonuniform spatial distribution of the atomic force microscope field. The kinetics of the decay of the microdomains are in qualitative agreement with the kinetics of the depolarization of the strontium-barium niobate solutions, which is observed by macroscopic methods.     

Temperature effects in x-ray photoelectron spectra of paramagnetic cupric and iron complexes with anomalous magnetic properties

The temperature dependence of the XPS spectra of paramagnetic cupric and iron complexes with anomalous magnetic properties is studied. It was found that the XPS spectra of polynuclear complexes with antiferromagnetic interaction, such as cupric acetate, do not change with temperature, although their magnetic moments diminish essentially. The Fe 2p spectra of mononuclear iron (III) complexes with the spin multiplicity transitions S = $\text{1}\text{2}$ ? S = $\text{5}\text{2}$ exhibit temperature-dependent reversible alterations of shake-up satellite intensity which correlate with the spin state of the paramagnetic Fe(III) ion. The results obtained prove the mechanism of appearance of intensive shake-up satellites in XPS spectra of paramagnetic 3d element complexes, which relates shake-up excitations with the interaction of the photoelectron with unpaired valence 3d electrons during photoionization.     

New parametric scattering in photorefractive Sr0.61Ba0.39Nb2O6:Cr

A new class of light-induced parametric scattering, not included in the conventional model, has been discovered in photorefractive Sr(0.61)Ba(0.39)Nb(2)O(6):Cr illuminated by two coherent beams. A novel model of multiwave mixing of coherent noise and transmitted light is developed to explain the new scattering phenomena. The model includes all known types and predicts a multitude of new types of parametric scattering. Generalized phase-matching conditions for parametric scattering in photorefractive crystals are proposed.     

Investigation of the structure and properties of sulfur-doped expitaxial gallium arsenide layers

Conclusion The electrophysical properties, the lattice constant, and the structure of sulfur doped epitaxial gallium arsenide layers were investigated using a complex of methods. The experimental data indicate that the sulfur atoms can exist in the GaAs lattice simultaneously in the number of states, namely, in the form of substitutional and interstitial solid solutions, as well as in the form of presegregations or second phase segregations. The concentration of interstitial sulfur atoms increases with the overall-sulfur content in the layers. At the maximum sulfur doping level second phase segregations are formed in the layers, which leads to an anamolous decrease in the lattice constant and the electron mobility.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 24–27, July, 1985.The authors wish to express their gratitute to L. G. Lavrent'eva for her interest and useful remarks.     

Synthesis and reactivity of metal-containing monomers 49. Synthesis and structure of low-valence transition metal acrylates and their polymers

The methods for synthesis of Cu¹⁺, Fe²⁺, Cr²⁺, and V³⁺ acrylates were elaborated. The compounds obtained were characterized by elemental analyses, data of IR, X-ray photoelectron, and Mössbauer spectroscopy, magnetochemistry, and mass spectrometry. Polymeric products were obtained by liquid-phase radical polymerization of metal acrylates. Changes in the electronic state of the ions and their nearest ligand environment during polymerization were observed.