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61.
The electronic structure and chemical bonding in the Sr2Fe2O5 strontium ferrate are investigated in the framework of the ab initio linear-muffin-tin-orbital tight-binding representation and extended Hükcel calculations. Models of defect formation (oxygen vacancies and anti-Frenkel defects) in the brownmillerite structure are considered. A model of ion transfer in strontium ferrate is proposed reasoning from the results of the calculations. 相似文献
62.
The temperature dependences of the velocity of longitudinal sound and internal friction in the ferromagnetic La0.5Pr0.2Ca0.3MnO3 single crystal with magnetic first-order phase transition were studied. It was found that the sound velocity decreases by ≈20% in transition from the ferromagnetic to paramagnetic state. In the paramagnetic region, the extended temperature hysteresis of the sound velocity and the internal friction was observed. It was shown that La0.5Pr0.2Ca0.3MnO3 has two paramagnetic phases with different sound velocities. 相似文献
63.
V. N. Krasil’nikov A. P. Shtin O. I. Gyrdasova E. V. Polyakov L. Yu. Buldakova M. Yu. Yanchenko V. M. Zainullina V. P. Zhukov 《Russian Journal of Inorganic Chemistry》2010,55(8):1184-1191
Ti1−x
V
x
O2−y
C
y
(0 ≤ x ≤ 0.10 and x = 0.50) whiskers having the anatase structure were synthesized via thermolysis of vanadium-doped titanium glycolate of composition
Ti1−x
V
x
(OCH2CH2O)2 (0 ≤ x ≤ 0.10 and x = 0.50). The starting reagents used to prepare Ti1−x
V
x
(OCH2CH2O)2 were mixtures of coprecipitated titanium and vanadyl hydroxides, which were heated in ethylene glycol at T ≤ 200°C: (1 − x)TiO(OH)2 + xVO(OH)2 + 2HOCH2CH2OH = Ti1−x
V
x
(OCH2CH2O)2 + 3H2O↑. Thermolysis of vanadium-doped titanium glycolate in various gas media over a wide range of temperatures is useful to prepare
titania samples doped with both vanadium and carbon to form a phase of the general composition Ti1 − x
V
x
O2 − y
C
y
whiskers prepared by thermolyzing Ti1 − x
V
x
(OCH2CH2O)2 in air at 450°C were found to have a high photocatalytic activity in hydroquinone oxidation in aqueous solutions irradiated
in the UV spectral range; the photocatalyst’s activity increases with increasing vanadium concentration. When hydroquinone
was irradiated in the blue, the maximal catalytic activity was discovered in a sample of composition Ti0.50V0.50O2−y
C
y
. Quantum-chemical calculations support experimental data that the double doping of titania (Ti1−x
V
x
O2−y
C
y
) enhances its photocatalytic activity compared to undoped anatase or anatase doped in one sublattice: Ti1−x
V
x
O2 and TiO2−y
C
y
. 相似文献
64.
Vladlen P. Zhukov Veronika M. Zainullina Vladimir G. Zubkov Alexander P. Tyutyunnik Tatiana A. Denisova 《ChemInform》2001,32(41):no-no
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option. 相似文献