91 research outputs found
AFM of metallic nano-particles and nano-structures in heavily irradiated NaCl
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
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
Phase transition in triglycine sulfate by piezoelectric response force microscopy and dielectric spectroscopy
Polarization switching kinetics at the nanoscale in ferroelectric copolymer Langmuir-Blodgett films
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
We have studied possible candidates for laser cooling transitions in
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
to upper states
at
410.6 nm and
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 and can be used for efficient laser cooling of
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 s for the rate of magnetic-dipole transition
at 1.14 m between the fine structure levels
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
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
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 and .Comment: 7 pages, 3 figure
Polarization switching kinetics of ferroelectric nanomesas of vinylidene fluoride-trifluoroethylene copolymer
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