http://dspace.nbuv.gov.ua:80/handle/123456789/114476 Fri, 24 Apr 2026 10:37:15 GMT 2026-04-24T10:37:15Z http://dspace.nbuv.gov.ua:80/bitstream/id/340956/ http://dspace.nbuv.gov.ua:80/handle/123456789/114476 http://dspace.nbuv.gov.ua:80/handle/123456789/118282 Negative dielectric permittivity of nonmagnetic crystals in the terahertz waveband Felinskyi, S.G.; Korotkov, P.A.; Felinskyi, G.S. Physical conditions for occurrence of the spectral bands with the negative dielectric permittivity in nonmagnetic crystalline media in the terahertz waveband have been studied in this work. It has been shown that damping the polar vibrations has a primary effect on formation of the negative dielectric permittivity in real crystals at resonance (terahertz) frequencies, and phonon attenuation imposes significant restrictions both on the frequency range and the minimum achievable value for all dielectric tensor components. Within frameworks of the single-oscillator model, the authors have obtained: i) the criterion for the existence of the negative dielectric permittivity, which is based on physical and spectroscopic parameters of the crystal, ii) analytical expressions for calculation of the frequency band where the dielectric permittivity takes negative values. Frequency regions and the minimum value of negative dielectric permittivity are quantitatively defined in the crystal LiTaO₃. It is proved the applicability of the obtained relationships in cases of relatively complex phonon vibration spectra. Sun, 01 Jan 2012 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/118282 2012-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/118281 Interaction between viral particles and structured metal surface under surface plasmon propagation Lozovski, V.; Lysenko, V.; Spivak, M.; Sterligov, V. The new method for decontamination of biological liquids (blood or blood plasma, for instance) from viruses is proposed. The method is based on the efficient attraction between nanoparticles and nanostructured surface, under which the surface plasmon-polaritons propagate. Sun, 01 Jan 2012 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/118281 2012-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/118279 Contribution of f- and g- transitions to electron intervalley scattering of n-S at temperatures 300 to 450 K Ermakov, V.M.; Kolomoets, V.V.; Panasyuk, L.I.; Nazarchuk, P.F.; Yashchynskiy, L.V. The change in mobility with increasing the temperature which may be due to the inclusion of gLO-phonon energy of 720K, is presented. In orientation of the uniaxial pressure X//[110]//J, g-transitions are attached in the directions [100] and [010]. The ftransitions are not completely removed from valleys located in the plane (100). In this case, there is no change in the slope of the dependence logρ vs. logT for the temperature range 300 to 450 K. So, no contribution of g-transitions to intervalley scattering occurs, while the observed is tha decisive role of f–transitions to this scattering. Sun, 01 Jan 2012 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/118279 2012-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/118277 Narrow-gap piezoelectric heterostructure as IR detector Sizov, F.F.; Smirnov, A.B.; Savkina, R.K.; Deriglazov, V.A.; Yakushev, M.V. Narrow-gap mercury cadmium telluride thin films grown by MBE and LPE methods onto various substrates (HgCdTe/Si, HgCdTe/GaAs, HgCdTe/CdZnTe) were investigated as a piezoelectric heterostructure for IR detection. The photoresponse, infrared transmittance spectra, parameters of the charge carrier transport, and mechanical properties were studied. Mechanical stresses at the layer-substrate interface were analyzed. HgCdTe-based infrared device is considered, operating in the middle (3–5 μm) infrared spectral range without cryogenic cooling to achieve performance level D* = 2.6 ⋅ 10⁹ ⋅ W⁻¹ cm ⋅Hz¹/² The possibility to detect infrared radiation is thought to be based on the possibility of the spatial separation of the non-equilibrium carriers in the strained semiconductor heterostructure with piezoelectric properties. Sun, 01 Jan 2012 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/118277 2012-01-01T00:00:00Z