Оттиски доступны непосредственно от издателя Фотокопирование разрешено только в соответствии с лицензией 2015 ИМФ (Институт металлофизики им. Г. В. Курдюмова НАН Украины) Напечатано в Украине.
Using the method of X-ray diffraction, the effect of shock-vibration treatment on the structural parameters and phase composition of mixtures of silicon dioxide and alpha iron oxide was studied. From these results, has been found that the shock-vibration treatment of oxides mixture leads to an increase in the coherent scattering region of crystalline α-Fe2O3. We obtained SEM images of composites before and after treatment. From the SEM images it is seen that the processing is accompanied by fragmentation of the aggregates, uniform placement of the nanoparticles between each other and the formation of new denser agglomerates. Electron-microscopic study of mixtures using TEM was performed, which showed that the treatment leads to a lay-up of particles each other with the formation of interatomic interaction between them, which is consistent with the results of ultra-soft X-ray emission spectroscopy. The electrochemical properties of LPS, with electrodes based on mixtures before and after treatment, in galvanostatic mode were investigated. It is found that the charge capacity of the LPS with the electrode based on the mixture with the maximum concentration of α-Fe2O3 after treatment is reduced by half.
Crystalline and electronic structures of SiO2/γ-Fe2O3 mixtures have been analyzed using X-ray diffraction (XRD) and ultra-soft X-ray emission spectroscopy (USXES). The energy redistribution of Fesрd, Sisp and Op valence electrons due to changes in the mass ratio (0,2 SiO2 + 0,8 γ-Fe2O3 , 0,5 SiO2 + 0,5 γ-Fe2O3, 0,8 SiO2 + 0,2 γ-Fe2O3) of SiO2 and α-Fe2O3 in the mixtures has been studied. The FeLα, SiLα and OKα ultra-soft X-ray emission spectra of SiO2/α-Fe2O3 mixtures were compared with those of individual iron oxide and silica powders. In analyzing these bands were detected shape similarity and the presence of identical elements of fine structure in OKα and FeLα-emission spectra, it shows a high degree of hybridization and Op- Fe3d - electronic valence states. Expansion OKα and FeLα-emission bands in the low energy side is the result of additional splitting energy Op- and Fe3d - levels with increasing degree of hybridization in the mehanoaktyvatsiynoyi processing.
In article present the results of low-temperature Mossbauer studies of iron (III) oxide/hydroxide nanocomposite synthesized by the method of deposition. Based on these studies, the composition of the synthesized composite was revealed. The nanodispersed composite with a specific surface 280 m2/g is a hematite in the weakly disordered crystalline state (CSR 10 nm), and a lepidocrocite in the X-ray amorphous state (particles size 3-4 nm). The relative integral intensity of the Zeeman sextet, which corresponds to the magnetically ordered phase of hematite, is practically unchanged and is about 17%. The tendency to divide the magnetically ordered component into two sextets, which differ in quadrupole splitting QS= –0.21 mm/s and QS= 0.21 mm/s, respectively, is observed starting from a temperature of 190 K. As a result of annealing of the synthesized material at a temperature of 200°C, a slight redistribution (≈ 5%) of the content of paramagnetic and magnetically ordered components was recorded, which indicates the structural stability of the nanoparticles of the lepidocrocite γ-FeOOH phase at this temperature. Increase of annealing temperatures to 500oC leads to the predicted course of the phase transition γ-FеООH ® α-Fе2О3. The mechanism of growth of hematite crystallites during sintering due to fixation side faces of larger α-Fe2O3 phase of nanoparticles of the γ-FeOOH phase with simultaneous transformation of their crystal structure to side faces of larger α-Fe2O3 phase particles is presented.
Crystalline and electronic structures of SiO2/Al2O3 mixtures have been analyzed using X-ray diffraction (XRD) and ultra-soft X-ray emission spectroscopy (USXES). Comparison of ultrasoft X-ray emission AlLα-, SiLα- and OKα-bands redistribution Alsp-, Sisp- and Op-valence electrons when changing the mass ratio (0,23Al2O3+0,77 SiO2;, 0,30Al2O3+0,70SiO2; 0,75Al2O3+25 SiO2) and depending on the method of obtaining them. Expansion OKα-emission bands showed an increase in population of Opπ-levels of oxygen in the formation of pyrogenic composites with different contents of aluminum oxide and silicon dioxide. Analysis AlLα-, SiLα- emission bands allowed to explain the increase of population Opπ-levels of oxygen and present the morphology formation of particles different of pyrogenic composites during synthesis.
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