[en] Data are presented on the radiothermoluminescence (RTL) (80-450 K) of BeO samples heat-treated between 1250 and 1750 K. The RTL curve of the samples shows a peak at 276 K, with an activation energy of 0.50 eV, which is due to a ferroelectric phase transition. The intensity of this peak is a linear function of gamma dose in the range 2 ≤D≤12 kGy, suggesting that heat-treated BeO is a candidate luminescent material for gamma dosimetry

[en] Full text: Radio thermoluminescence (RTL) of oxide layer of aluminum being created during radiation-thermal oxidation in Al- ads. H₂O system between 80-400 K temperature was investigated. As the research object a metallic of aluminum plates by mark AD-00, was exposed oxidation under γ -radiation at 373 K temperature. Previous samples were vacuumized at T=300 K temperature and P=10^-4Pa pressure. For RTL analysis of samples radiated till doze 25 kGy by γ-rays ⁶⁰Co of at 1.03 Gys^-1 doze rate and 77 K. Curves RTL were got in TLG-69 thermoluminograph at 5Kmin^-1 warming velocity of samples. Surface condition and oxidation degree were controlled by IRRAS and XPS methods. Al plates vacuumized, radiation-thermal (RT) oxidated at room temperature were irradiated by γ-quanta at 77K, it leads to the appearance of peaks RTL got at low temperature -170, 230 and 320 K. The most intensive peak at T=170K with activation energy E_a=0.38eV, and also weak peak at T = 230K, it may connect with the generation of unstable O₃^- complex. The generation of O₃^- complex is due to low-temperature adsorption of molecules O₂ - radiation-heterogeneous decomposition product of H₂O surface localized O^- hole center or V^- type one (O^- ion lattice being near cation vacancy). We think the wide diffusion of RTL peak at 320K with E_a ≅ 0.8-1.0eV links with the adsorption complexes of H (hydroxyl or ion hydride) being close to anion vacancy with V(V_OH, V^-, V_Al and others) type hole center. While increasing contact time between Al and water radiation-thermal oxidated and the thickness of oxide layers, intensity of peak gets low at 300K, that's proper to the results of the IR- spectroscopic researches. By increasing the thickness of oxide layer RTL peaks intensity gets high at 170 K, this links with increasing of surface hole center density and formation possibility of oxygen adsorption complexes. Intensity of the peak given depends on the doze of γ-rays and in the region 2≤ D≤ 20 kGy linear correlation is observed between them, in the region D> 20 kGy saturation is done. Vacuumization of the samples at 673K makes RTL entirely depress. Thus during studying the contact of RT oxidation of metals with water RTL method can be applied. While the formation of oxide layer the leading role of oxygen was determined

[en] Full text: In present paper the peculiarities of radiation and radiation-thermal hexane conversion processes on the surface of aluminum have been studied. A spectro-kinetic investigations are carried out using the IR reflection - adsorption spectroscopy method. The formation of molecular hydrogen (H₂) and other decomposition products is controlled chromatographically.The thin polished aluminum plates of the mark AD-00 were used as the test material. Spectroscopically pure hexane was used. The samples were irradiated by ⁶⁰Co γ-rays with a radiation dose 1.03 Gy/s. Analysis of IR reflection-adsorption spectra of adsorbed hexane (C₆H₁₄) at temperature range 300-673 K on the surface of aluminum is indicated on formation a H-bonded hydrocarbon complex (ν∼2680 cm^-1) with C-H bond loose and proceeding of possibility of dissociative adsorption with formation of the methyl alkyls (ν∼2880, 2920, 2970 cm^-1). The probability of last process proceeded on defect centers increases with increasing of the interaction temperature. It was established, that the radiation processes in hetero system Al/ads. C_6H14 accelerate the radiolysis of the hexane. Along with molecular H₂ also hydrocarbons an C₁-C₅ also are. This is testified by appearance in IR spectra the bands of pendulum modes of (CH₂)n, where with n>6 maxima 770, 790, 825, 900 and 950 cm^-1. The rates of surface decomposition processes increase with temperature increasing. Based on the experimental data, a possible mechanisms of the hexane radiation-heterogeneous decomposition on the surface of aluminum are suggested

No abstract available

[en] The oxidation of aluminum in the aluminum-water system under ⁶⁰Co γ radiation with doses 0.5 to 120 kGy at a dose rate of 1.03 Gy/s was studied using the radiothermoluminescence and IR reflection-absorption spectroscopy methods. The specific features of the radiothermoluminescence peaks observed in a 100-250 K temperature range (the activation energy E _a 0.38-0.65 eV) corroborate the significant role of superficial oxygen hole-type centers and chemisorbed oxygen in the oxide film formation. Based on the dose dependence of the chemisorbed oxygen thermal quenching, the kinetics of radiation-induced aluminum oxidation and its chemisorptive passivation are revealed. The oxide film formation and the heterogeneity of its structure are traced using the IR reflection spectra. A possible scheme of the radiation oxidation of aluminum in the aluminum-water system is suggested

[en] Full text: In present work for the purpose of revealing the peculiarities of radiation, thermal radiation and thermal processes in contact of aluminum materials of the nuclear reactors with water heat bearer have the kinetics of aluminum oxidation and of accumulation of molecular hydrogen (H₂) under γ-irradiation at temperatures T=300-973 K have been studied. The spectro-kinetic investigation of aluminum surface oxidation by water is carried out using the IR reflection-adsorption spectroscopy. The yield of molecular H₂ is defined by chromatography. The objects of consideration were the thin polished aluminum plates marked AD-00 and spectroscopically pure bi-distillated water. Samples were irradiated with ⁶⁰Co γ-rays at a radiation dose 6.67 Gy/s. On the basis of spectroscopic data it is set up that in the result of the interaction of the water and its decomposition products with aluminum on its surface the oxide phase 1200-650 cm^-1, hydroxyl cover 3800-300 cm^-1 and hydride phase 900-1600 cm^-1 are formed. It was established, that the radiation processes in the hetero-system Al/ads.H₂O accelerate the radiolysis of water. With temperature increasing a rates of surface aluminum oxidation and accumulation of H₂ processes increase, however at temperatures T≥973 K the oxidation process has a bulk character. At this temperature region the contribution of the radiation processes is imperceptible. The activation energies (E_a) of the radiation-thermal and thermal processes of the formation H₂ and aluminum oxidation at T<873 K are defined, and they are 4.5 and 14.5 kJ /mol accordingly. Yield of H₂ in hetero-system Al/ads. H₂O is equal to G(H₂)=2.25 molecule/100 eV. It is discovered, that after certain contact time same part of H₂ is accumulated in metal in hydride form

[en] This paper presents the results of IR spectroscopic studies of radiation-stimulated adsorption of water in heterogeneous systems BeO/adsH₂O and γAl₂O₃/adsH₂O at room temperature. The spectrokinetic dependences pf the relative optical densities of the bands of hydroxyl (OH) groups and water molecules on the dose of gamma irradiation have been studied. It is shown that the presence of wells in the region of low doses for intermediate particles and water molecules, the occurence and difference of their depths, as well as the change in their half-widths indicate the difference in relaxation tomes associated with difference in the nature of the interaction of these particles and water molecules with surface radiation defects.

[en] IR reflection-absorption spectroscopy was used to examine the regularities of radiation-stimulated absorption of n-hexane on an aluminum surface. γ-Irradiation of an aluminum surface at room temperature produces sites capable of adsorbing n-hexane by the molecular and dissociative mechanisms. The kinetics of the adsorption of n-hexane on aluminum γ-irradiated with doses of 5 to 25 Gy is indicative of activated dissociative chemisorption accompanied by the formation of aluminum alkyls and surface hydrides. A feasible mechanism for the process was proposed

No abstract available

[en] The kinetics of radiation, radiation-thermal, and thermal oxidation of metal and accumulation of H₂ was investigated in the reaction of aluminum with water at 300-973 K. It was found that radiation processes in contact of aluminum with water accelerated radiolysis of water. The rates of surface oxidation of aluminum and accumulation of H₂ increase with an increase in the temperature, and oxidation is destructive at T ≥ 900 K. The kinetic parameters were determined and mechanisms of the processes were proposed. 14 refs., 3 figs