Fabrication of composite based on GeSi with Ag nanoparticles using ion implantation

Comparative analysis of the structural and optical properties of composite layers fabricated with the aid of implantation of single-crystalline silicon (c-Si) using Ge⁺ (40 keV/1 × 10¹⁷ ions/cm²) and Ag⁺ (30 keV/1.5 × 10¹⁷ ions/cm²) ions and sequential irradiation using Ge⁺ and Ag⁺ ions is presented. The implantation of the Ge⁺ ions leads to the formation of Ge: Si fine-grain amorphous surface layer with a thickness of 60 nm and a grain size of 20–40 nm. The implantation of c-Si using Ag⁺ ions results in the formation of submicron porous amorphous a-Si structure with a thickness of about 50 nm containing ion-synthesized Ag nanoparticles. The penetration of the Ag⁺ ions in the Ge: Si layer stimulates the formation of pores with Ag nanoparticles with more uniform size distribution. The reflection spectra of the implanted Ag: Si and Ag: GeSi layers exhibit a sharp decrease in the intensity in the UV (220–420 nm) spectral interval relative to the intensity of c-Si by more than 50% owing to the amorphization and structuring of surface. The formation of Ag nanoparticles in the implanted layers gives rise to a selective band of the plasmon resonance at a wavelength of about 820 nm in the optical spectra. Technological methods for fabrication of a composite based on GeSi with Ag nanoparticles are demonstrated in practice.     

Antiferromagnetic interactions in single crystalline Zn1-xCoxO thin films

In a rather contradictory situation regarding magnetic data on Co-doped ZnO, we have succeeded in fabricating high-quality single crystalline Zn(1-x)Co(x)O (x=0.003-0.07) thin films. This gives us the possibility, for the first time, to examine the intrinsic magnetic properties of ZnO:Co at a quantitative level and therefore to address several unsolved problems, the major one being the nature of the Co-Co interaction in the ZnO structure.     

3-Cyanoazolo[5,1-c][1,2,4]triazines: synthesis and antiviral activity

Chemistry of Heterocyclic Compounds - A series of azolo[5,1-c][1,2,4]triazines containing a cyano group were prepared as analogs of the drug Triazavirin (riamilovir). Sodium...     

Magnetoactive elastomer based on magnetically hard filler: Synthesis and study of viscoelastic and damping properties

This work is focused on the magnetic response of magnetoactive elastomer (MAE) based on silicone polymer matrices filled with magnetic particles of magnetically hard NdFeB-alloy. Viscoelastic properties of MAE were studied by the method of oscillation shear. After magnetization in an external magnetic field of 2 T MAE samples demonstrate more than two-time increase in the storage and loss moduli and 25% increase in the loss factor. Performed study of the damping properties of the materials has shown that the oscillation time of the pendulum hammering the magnetized sample is in two times shorter than in case of the non-magnetized sample. Viscoelastic and damping properties of MAE are defined by magnetic interactions between the magnetized particles of the magnetic filler.     

Kinetics and Mechanism of Thermal Decomposition of 1-(Dinitromethyl)-3-R-1H-1,2,4-triazoles

Russian Journal of General Chemistry - Kinetic regularities and the mechanism of thermal decomposition of 3-substituted 1-(dinitromethyl)1H-1,2,4-triazoles in the solid phase and in dibutyl...     

Decoupling approximations for quantum vibrational predissociation dynamics: The tests on the low-level golden rule approaches for some rare gas—Cl2, ICl complexes

Vibrational and rotational decoupling approximations are tested in three-dimensional Fermi Golden Rule calculations on energies, lifetimes, and product state distributions of the vibrationally predissociating atom—diatom van der Waals complexes. The validity of approximate separations of diatom vibration, decoupling of stretching and bending intermolecular motions, and rotational infinite order sudden approximation for product scattering is characterized by comparison with the results of accurate calculations on the Ne ··· Cl₂, Ne ··· ICl, and He ··· ICl systems. The most accurate approximate schemes are recommended. © 1996 by John Wiley & Sons, Inc.     

Development of the activation process model: Compensation effect

In this article, an attempt was made to develop an activation process model. The average energy of the translational motion of the atoms, taking part in the elementary activation process and being in the thermodynamic equilibrium with thermal radiation, was obtained using the quantum canonical Gibbs distribution and the model principles of elementary activation. The degeneracy and exclusion of some excited vibrational levels were taken into consideration, the result being a strong dependence of the probability of surmounting the activation barrier on the behavior of the excited vibrational states of the quantum subsystems. As an application of the development model, the formulas of the preexponential factor for solid-state atomic diffusivity and first-order chemical reaction rate constants were derived. Quantitative analysis of the atomic diffusion in solids in the framework of our model has made it possible to describe the diffusion processes in metals, covalent semiconductors, as well as diffusion anomalies, connected with the “nonclassical” behavior of the empirical Arrhenius dependence. A possible physical essence of a kinetic compensation effect is discussed. It was shown that compensation may be caused by only changing the degeneracy of the vibrational levels of the quantum subsystems. © 1996 John Wiley & Sons, Inc.     

Underground Physics and the Nonlinear Delayed Barometric Effect of the Gamma-Ray Background

Journal of Experimental and Theoretical Physics - The electronic, magnetic, and optical properties of MnGa2O4 in the structure of the normal and inverse spinels are subjected to an ab initio...     

A Study of the Protective Properties of a Combined Cermet Material upon a High-Speed Impact

Technical Physics - The ballistic resistance of a combined cermet material based on a high-hardness ceramic bound with an intermetallide on a high-strength metal substrate, (TiB2 + NiTi) + Ti, is...     

Translational Motion of Water Molecules near the Interface between Gas and Condensed Matter Using the Self-Similarity Effect and 4D Space

Bulletin of the Lebedev Physics Institute - Abstract—The self-similarity effect during rarefied water vapor flow between two finite-volume vessels is repeatedly recorded with a similarity...