Formation of disperse particles under high-power ion beam irradiation of metals with a coating

Metal systems based on aluminum and copper coated with nickel irradiated by a high-power ion beam of nanosecond duration have been studied by scanning electron microscopy and local X-ray microanalysis. Dispersed particles of micro- and nanosizes have been found on the surface target. Their composition and formation mechanism differ. It has been shown that microparticles were formed during mixing of film and target atoms and consisted of corresponding components. Nanoparticles were mainly composed of the coating material, and their formation was associated with the dispersion of the Ni film due to the presence of a thin oxide layer on the sample surface. The deposition of Ni ablated by a high-power ion beam can affect the formation of nanoparticles.     

On a toroidal pendulum

We consider the problem of motion of a heavy particle on the surface of a torus with horizontal axis of rotation.     

Degradation and recovery of the external quantum efficiency of organic photovoltaic structure

Crystallography Reports - The photosensitivity of a mixed composition of donor CuPc and acceptor C60, its degradation in time (for 16 months), and partial recovery (issues that were out of...     

Observation of the bottomonium ground state in the decay Upsilon(3S)-->gammaetab

We report the results of a search for the bottomonium ground state etab(1S) in the photon energy spectrum with a sample of (109+/-1) million of Upsilon(3S) recorded at the Upsilon(3S) energy with the BABAR detector at the PEP-II B factory at SLAC. We observe a peak in the photon energy spectrum at Egamma=921.2(-2.8)+2.1(stat)+/-2.4(syst) MeV with a significance of 10 standard deviations. We interpret the observed peak as being due to monochromatic photons from the radiative transition Upsilon(3S)-->gammaetab(1S). This photon energy corresponds to an etab(1S) mass of 9388.9(-2.3)+3.1(stat)+/-2.7(syst) MeV/c2. The hyperfine Upsilon(1S)-etab(1S) mass splitting is 71.4(-3.1)+2.3(stat)+/-2.7(syst) MeV/c2. The branching fraction for this radiative Upsilon(3S) decay is estimated to be [4.8+/-0.5(stat)+/-1.2(syst)]x10(-4).     

Specific Features of Synthesis,Structure, Magnetometry,and NMR Spectroscopy of Different-Type Nanowires

Physics of the Solid State - Nanowires of different types (homogeneous (made of iron) and heterogeneous (layered)), obtained by the template synthesis method, have been investigated. A technique...     

Switching time dispersion and retention of bistable states in Langmuir-Blodgett ferroelectric films

Polarization switching and retention of each of the two polarized states in Langmuir—Blodgett (LB) ferroelectric films are studied using nonlinear dielectric spectroscopy. It is found that polarized states can be preserved for a long time, but the polarization dynamics in 10–40-nm-thick LB films is characterized by a considerable switching-time dispersion. In addition, ferroelectric LB films exhibit clearly manifested asymmetry of switching to states with opposite directions of polarization. To explain the experimental results, a polarization-switching model is proposed that takes into account the energy of interaction of a ferroelectric polymer with boundary surfaces. The effect of inhomogeneity of the LB film structure on the ferroelectric switching dynamics is also discussed.     

Adsorption of fatty acids from solutions in organic solvents on the surface of finely dispersed magnetite: 1. Isotherms of adsorption of oleic,linoleic, and linolenic acid from carbon tetrachloride and hexane

Isotherms of adsorption of oleic, linoleic, and linolenic acids on magnetite from solutions in carbon tetrachloride and hexane are measured. When CCl₄ is used as a solvent, the adsorption values increase in the following order: oleic, linoleic, and linolenic acid. In the case of hexane, the order is opposite. Adsorption isotherms of the fatty acids on aggregated magnetite are described in terms of the theory of volume filling of micropores. It is disclosed that, in the case of CCl₄ , the limiting adsorption values and characteristic energies of the process increase in a series: oleic, linoleic, and linolenic acid, but in the case of hexane, they decrease in the same sequence. Upon the adsorption of fatty acids from solutions in CCl₄ and hexane on finely dispersed magnetite, molecules of the acids and solvents compete for the active sites on the adsorbent surface. The number of double bonds in the molecules of unsaturated fatty acids and the desolvation of both the adsorbent surface and adsorbate molecules substantially affect the adsorption of these acids. The effect of the solvents is most pronounced for the adsorption of oleic acid, decreasing with a rise in the number of double bonds in a fatty acid molecule.Translated from Kolloidnyi Zhurnal, Vol. 66, No. 6, 2004, pp. 779–783.Original Russian Text Copyright © 2004 by Korolev, Ramazanova, Yashkova, Balmasova, Blinov.