91 research outputs found

    AFM of metallic nano-particles and nano-structures in heavily irradiated NaCl

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    AFM investigations are reported for heavily, electron irradiated NaCl crystals in ultra high vacuum (UHV) in the non-contact mode with an UHV AFM/STM Omicron system. To avoid chemical reactions between the radiolytic Na and oxygen and water, the irradiated samples were cleaved and prepared for the experiments in UHV. At the surface of freshly cleaved samples, we have observed sodium nano-precipitates with shapes, which depend on the irradiation dose and the volume fraction of the radiolytic Na. It appears that the nano-structures consist of (i) isolated nano-particles, (ii) more or less random aggregates of these particles, (iii) fractally shaped networks and (iv) ‘‘fabrics’’ consisting of bundles of Quasi-1D arrays forming polymeric networks of nano-particles. Almost independent of the concentration of the metallic Na in the samples the size of the individual nano-particles is in the range 1–3 nm. Our new AFM results are fully in line with our CESR and previous Raman scattering results.

    Development of laboratory information management system

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    Results of the actual direction of work of Scientific Research Institute of HV on development of the program complex LIS/LIMS «Chemist - analysts» for automatization of activity of analytical laboratories are presented. Functions of the complex and methodological principles of its development are considered, comparison with foreign analogues is carried out. The model of the industrial analytical control with use of concepts of a life cycle of a laboratory, technique and test is described

    Polarization switching kinetics at the nanoscale in ferroelectric copolymer Langmuir-Blodgett films

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    The polarization switching kinetics of ferroelectric Langmuir–Blodgett films of vinylidene fluoride-trifluoroethylene copolymer were investigated by piezoresponse force microscopy with a resolution of 100 nm. The switching time in response to a localized voltage pulse exhibits an exponential dependence on reciprocal voltage, which is consistent with nucleation-limited switching dynamics

    Blue laser cooling transitions in Tm I

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    We have studied possible candidates for laser cooling transitions in 169^{169}Tm in the spectral region 410 -- 420 nm. By means of saturation absorption spectroscopy we have measured the hyperfine structure and rates of two nearly closed cycling transitions from the ground state 4f136s2(2F0)(Jg=7/2)4\textrm{f}^{13}6\textrm{s}^2(^2\textrm{F}_0)(J_g=7/2) to upper states 4f12(3H5)5d3/26s2(Je=9/2)4\textrm{f}^{12}(^3\textrm{H}_5)5\textrm{d}_{3/2}6\textrm{s}^2(J_e=9/2) at 410.6 nm and 4f12(3F4)5d5/26s2(Je=9/2)4\textrm{f}^{12}(^3\textrm{F}_4)5\textrm{d}_{5/2}6\textrm{s}^2(J_e=9/2) at 420.4 nm and evaluated the life times of the excited levels as 15.9(8) ns and 48(6) ns respectively. Decay rates from these levels to neighboring opposite-parity levels are evaluated by means of Hartree-Fock calculations. We conclude, that the strong transition at 410.6 nm has an optical leak rate of less then 21052\cdot10^{-5} and can be used for efficient laser cooling of 169^{169}Tm from a thermal atomic beam. The hyperfine structure of two other even-parity levels which can be excited from the ground state at 409.5 nm and 418.9 nm is also measured by the same technique. In addition we give a calculated value of 7(2)7(2) s1^{-1} for the rate of magnetic-dipole transition at 1.14 μ\mum between the fine structure levels (Jg=7/2)(Jg=5/2)(J_g=7/2)\leftrightarrow(J'_g=5/2) of the ground state which can be considered as a candidate for applications in atomic clocks.Comment: 8 pages, 5 figure

    PFM studies of ferroelectric phase transition in superprotonic (K0.43(NH4)0.57)3H(SO4)2 crystals

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    This work was supported by the Ministry of Science and Higher Education within the State assignment FSRC «Crystallography and Photonics» RAS and the Presidium of the Russian Academy of Sciences, Basic Research Program 1.2.P no. 32

    Ionization of highly charged relativistic ions by neutral atoms and ions

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    Ionization of highly charged relativistic ions by neutral atoms and ions is considered. Numerical results of recently developed computer codes based on the relativistic Born and the equivalent-photon approximations are presented. The ionization of the outer shells dominate. For the outer projectile electron shells, which give the main contribution to the process, the non-relativistic Schr\"odinger wave functions can be used. The formulae for the non-relativistic reduction of the Dirac matrix-elements are obtained for ionization of electrons with arbitrary quantum numbers nn and \ell.Comment: 7 pages, 3 figure
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