排序方式: 共有95条查询结果,搜索用时 215 毫秒
21.
A. M. Vorotynov G. A. Petrakovskii D. A. Velikanov L. V. Udod M. S. Molokeev 《Physics of the Solid State》2012,54(9):1796-1799
New single crystals of Li8FeSm22O38 have been grown by spontaneous crystallization from a solution in melt. The structure of these crystals has been determined: it corresponds to the space group Im $\bar 3$ m. Investigations of the magnetic susceptibility in the ranges of temperatures 2?C24 K and fields up to 50 kOe have revealed a magnetic transition near 3 K. The temperature behavior of the magnetic susceptibility of the two-level system has been simulated. The results of the simulation agree with the experimental data. The resonance properties of Li8FeSm22O38 have been studied in the temperature range 100?C300 K. 相似文献
22.
A. V. Ruseikina L. A. Solovyov M. S. Molokeev O. V. Andreev 《Russian Journal of Inorganic Chemistry》2012,57(1):79-83
The compound sulfides EuLnCuS3 (Ln = Nd and Sm) were obtained for the first time. Their crystal structures were determined from X-ray powder diffraction data. The crystals of both compounds are orthorhombic (space group Pnma). The compound EuNdCuS3 is isostructural with BaLaCuS3; the unit cell parameters are a = 11.0438(2) Å, b = 4.0660(1) Å, c = 11.4149(4) Å. The compound EuSmCuS3 is isostructural with Eu2CuS3; the unit cell parameters are a = 10.4202(2) Å, b = 3.9701(1) Å, c = 12.8022(2) Å. 相似文献
23.
Yuriy G. Denisenko Victor V. Atuchin Maxim S. Molokeev Alexander E. Sedykh Nikolay A. Khritokhin Aleksandr S. Aleksandrovsky Aleksandr S. Oreshonkov Nikolai P. Shestakov Sergey V. Adichtchev Alexey M. Pugachev Elena I. Salnikova Oleg V. Andreev Illaria A. Razumkova Klaus Müller-Buschbaum 《Molecules (Basel, Switzerland)》2022,27(13)
Praseodymium sulfate was obtained by the precipitation method and the crystal structure was determined by Rietveld analysis. Pr2(SO4)3 is crystallized in the monoclinic structure, space group C2/c, with cell parameters a = 21.6052 (4), b = 6.7237 (1) and c = 6.9777 (1) Å, β = 107.9148 (7)°, Z = 4, V = 964.48 (3) Å3 (T = 150 °C). The thermal expansion of Pr2(SO4)3 is strongly anisotropic. As was obtained by XRD measurements, all cell parameters are increased on heating. However, due to a strong increase of the monoclinic angle β, there is a direction of negative thermal expansion. In the argon atmosphere, Pr2(SO4)3 is stable in the temperature range of T = 30–870 °C. The kinetics of the thermal decomposition process of praseodymium sulfate octahydrate Pr2(SO4)3·8H2O was studied as well. The vibrational properties of Pr2(SO4)3 were examined by Raman and Fourier-transform infrared absorption spectroscopy methods. The band gap structure of Pr2(SO4)3 was evaluated by ab initio calculations, and it was found that the valence band top is dominated by the p electrons of oxygen ions, while the conduction band bottom is formed by the d electrons of Pr3+ ions. The exact position of ZPL is determined via PL and PLE spectra at 77 K to be at 481 nm, and that enabled a correct assignment of luminescent bands. The maximum luminescent band in Pr2(SO4)3 belongs to the 3P0 → 3F2 transition at 640 nm. 相似文献
24.
Golovnev N. N. Molokeev M. S. Sterkhova I. V. Lesnikov M. K. 《Russian Journal of Coordination Chemistry》2019,45(8):569-572
Russian Journal of Coordination Chemistry - The structure of the complex [Cu(Bipy)2(BA)] ? 7H2O (I), where Bipy is 2,2'-dipyridyl, and BA2– is the barbituric acid anion (H2BA), is... 相似文献
25.
E. V. Bogdanov E. I. Pogoreltsev S. V. Mel’nikova M. V. Gorev I. N. Flerov M. S. Molokeev A. V. Kartashev A. G. Kocharova N. M. Laptash 《Physics of the Solid State》2013,55(2):409-418
Thermal, physical, structural, optical, and dielectric investigations have been performed for oxyfluoride solid solutions (NH4)2W1 — x Mo x O2F4 (x = 0, 0.1, 0.2, 0.3, 0.4, 0.6, 0.8, 1). The character of the influence of the chemical and hydrostatic pressures on the stability of the parent (space group Cmcm) and distorted ferroelastic and antiferroelectric phases has been determined by analyzing the temperature-pressure, unit cell volume-composition, and temperature-composition phase diagrams. The specific features of the nature and mechanism of the phase transitions have been discussed using the available data on the structural, entropy, and dielectric parameters. 相似文献
26.
I. A. Yakovlev S. N. Varnakov B. A. Belyaev S. M. Zharkov M. S. Molokeev I. A. Tarasov S. G. Ovchinnikov 《JETP Letters》2014,99(9):527-530
The results of the structural and magnetic studies of the epitaxial structure prepared during the simultaneous evaporation from two iron and silicon sources on an atomically pure Si(111)7 × 7 surface at a substrate temperature of 150°C have been presented. The epitaxial structure has been identified as a single-crystal Fe3Si silicide film with the orientation Si[111]‖Fe3Si[111] using methods of the X-ray structural analysis, transmission electron microscopy, and reflection high-energy electron diffraction. It has been established that the epitaxial Fe3Si film at room temperature has magnetic uniaxial anisotropy (H a = 26 Oe) and a relatively narrow uniform ferromagnetic resonance line (ΔH = 11.57 Oe) measured at a pump frequency of 2.274 GHz. 相似文献
27.
T. V. Drokina G. A. Petrakovskii D. A. Velikanov M. S. Molokeev 《Physics of the Solid State》2014,56(6):1131-1136
The results of the experimental investigation of the magnetic properties of the SmFeGe2O7 compound have been presented. It has been found that the temperature dependence of the susceptibility exhibits two features that coincide with the anomalies in the temperature dependence of the specific heat and indicate magnetic phase transitions in SmFeGe2O7. The external magnetic field induces a magnetic transition, the critical field of which depends on the temperature. 相似文献
28.
A. V. Malakhovskii V. V. Sokolov A. L. Sukhachev A. S. Aleksandrovsky I. A. Gudim M. S. Molokeev 《Physics of the Solid State》2014,56(10):2056-2063
Single crystals of the ErFe3(BO3)4 borate were synthesized and their structure was studied. Absorption spectra of the Er3+ ion in σ- and π-polarizations of f-f transitions 4 I 15/2 → 4 I 13/2, 4 I 11/2, 4 I 9/2, 4 F 9/2, 4 S 3/2, 2 H 11/2, and 4 F 7/2 were measured. The refractive index and birefringence were measured as a function of the wavelength. The transition intensities were analyzed within the Judd-Ofelt theory, and the following parameters of the theory were obtained: Ω2 = 7.056 × 10?20 cm2, Ω4 = 1.886 × 10?20 cm2, and Ω6 = 2.238 × 10?20 cm2. Using these parameters, the radiative transition probabilities, luminescence branching ratios, and radiative lifetimes of multiplets were calculated. 相似文献
29.
The crystal structures of cesium 2-thiobarbiturate C4H3CsN2O2S (I) and rubidium 2-thiobarbiturate C4H3N2O2RbS (II) (C4H4N2O2S is 2-thiobarbituric acid, H2TBA) have been determined. Isostructural crystals are monoclinic; a = 7.9609(3) Å,b = 11.8474(3) Å, c = 7.7317(2) Å, β = 101.285(3)°, V = 715.13(4) Å3, space group C2/m, Z = 4 for I and a = 7.6369(2) Å, b = 11.7690(3) Å, c = 7.5568(2) Å, β = 100.212(1)°, V = 668.44(3) Å3, space group C2/m, Z = 4 for II. Each metal ion in complexes I and II is bonded to four oxygen atoms and two sulfur atoms at the vertices of a six-vertex polyhedron. N-H…O hydrogen bonds link HTBA-ions into chains. The structure is also stabilized by the “head-to-tail” π-π interaction of HTBA-ions. 相似文献
30.
M. S. Molokeev S. V. Misyul’ V. D. Fokina A. G. Kocharova K. S. Aleksandrov 《Physics of the Solid State》2011,53(4):834-839
The structures of three phases of the K3WO3F3 crystal have been determined from X-ray diffraction data obtained for a powder sample. The profile and structural parameters
have been refined according to the technique implemented in the DDM program. The results obtained have been discussed using
the group-theoretical analysis of the complete order parameter condensate, which takes into account the critical and noncritical
atomic displacements and allows the interpretation of the experimental data. The sequence of structural transformations is
found to be as follows: $
Fm\bar 3m\xrightarrow[{(\eta _1 ,0,0)}]{{11 - 10(\Gamma _4^ - )}}I4mm\xrightarrow[{(\eta _1 ,\eta _2 ,0)}]{{11 - 10(\Gamma _4^ - )}}Cm
$
Fm\bar 3m\xrightarrow[{(\eta _1 ,0,0)}]{{11 - 10(\Gamma _4^ - )}}I4mm\xrightarrow[{(\eta _1 ,\eta _2 ,0)}]{{11 - 10(\Gamma _4^ - )}}Cm
. 相似文献