http://dspace.nbuv.gov.ua:80/handle/123456789/115380 2026-04-23T17:37:12Z http://dspace.nbuv.gov.ua:80/handle/123456789/117133 The influence of the disordered dipole subsystem on the thermal conductivity of the CO solid at low temperatures Sumarokov, V.; Jeżowski, A.; Stachowiak, P. The thermal conductivity of solid CO was investigated in the temperature range 1–20 K. The experimental temperature dependence of thermal conductivity of solid CO was described using the time-relaxation method within the Debye model. The comparison of the experimental temperature dependences of the thermal conductivity of N₂ and CO shows that in the case of CO there is an additional large phonon scattering at temperatures near the maximum. The analysis of the experimental data indicates that this scattering is caused by the frozen disordered dipole subsystem similar to a dipole glass. The scattering is described by the resonant phonon scattering on tunnelling states and on low-energy quasi-harmonic oscillations within the soft potential model. 2009-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/117132 Structure of nitrous oxide-carbon dioxide alloys Solodovnik, A.A.; Danchuk, V.V. Structure of N₂O–CO₂ solid mixtures was investigated by transmission electron diffraction over the entire range of their mutual concentrations. In the temperature range 5–65 K the experimental data indicate no phase separation in these alloys. The average structure of the solutions belongs to the Pa3 symmetry. The behavior of the concentration dependence of the lattice parameter has a nonmonotonic character, displaying a sharp step, the positions of which on the concentration scale depends on the deposition temperature. A possible explanation of this phenomenon is suggested. 2009-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/117131 Electron traps in solid Xe Khyzhniy, Ivan V.; Uyutnov, Sergey A.; Savchenko, Elena V.; Gumenchuk, Galina B.; Ponomaryov, Alexey N.; Bondybey, Vladimir E. Correlated real-time measurements of thermally stimulated luminescence and exoelectron emission from solid Xe pre-irradiated with an electron beam were performed. The study enabled us to distinguish between surface and bulk traps in solid Xe and to identify a peak related to electronically induced defects. The activation energy corresponding to annihilation of these defects was estimated by the following methods: the method of different heating rates, the initial-rise method, and the curve cleaning technique with fitting of the thermally stimulated luminescence glow curve. 2009-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/117130 Cryocrystal phase transitions applied as temperature standards Szmyrka-Grzebyk, A.; Kowal, A. International temperature scales define several fixed points, which temperature values are determined with a very high precision. Some of them, which are in a low-temperature range, are called gaseous fixed points because the reference substances under a normal condition — in a room-temperature range — appear in a gaseous state. These reference substances are called by physicists cryocrystals or quantum crystals when occurring in a low temperature in a solid state. The substances play an important role in a standard thermometry. The triple point of argon, oxygen, neon and hydrogen are primary fixed points of the International Temperature Scale of 1990 (ITS-90) [1]. The triple points of nitrogen, methane and carbon dioxide are secondary fixed points of the scale [2]. Also, the solid–solid phase transitions in the cryocrystals are secondary fixed points of the scale. The highest accuracy methods of measurements applied in a standard thermometry enable the determination with a very small uncertainty of the phase transition temperatures, its reproducibility and stability. The reproducibility and stability of the transition temperature are the most important factors deciding about usefulness of these points in thermometry. Using the highest accuracy methods, better than 1 mK, which at present are used in metrology only can give a new information about nature and properties of investigated substances important also for physicists. 2009-01-01T00:00:00Z