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1.
Skripov AV Mushnikov NV Terent'ev PB Gaviko VS Udovic TJ Rush JJ 《J Phys Condens Matter》2011,23(40):405402
The vibrational spectrum of hydrogen and the parameters of H jump motion in the rhombohedral Th(2)Zn(17)-type compound Ce(2)Fe(17)H(5) have been studied by means of inelastic and quasielastic neutron scattering. It is found that hydrogen atoms occupying interstitial Ce(2)Fe(2) sites participate in the fast localized jump motion over the hexagons formed by these tetrahedral sites. The H jump rate τ(-1) of this localized motion is found to change from 3.9 × 10(9) s(-1) at T = 140 K to 4.9 × 10(11) s(-1) at T = 350 K, and the temperature dependence of τ(-1) in the range 140-350 K is well described by the Arrhenius law with the activation energy of 103±3 meV. Our results suggest that the hydrogen jump rate in Th(2)Zn(17)-type compounds strongly increases with decreasing nearest-neighbor distance between the tetrahedral sites within the hexagons. Since each such hexagon in Ce(2)Fe(17)H(5) is populated by two hydrogen atoms, the jump motions of H atoms on the same hexagon should be correlated. 相似文献
2.
T. V. Kuznetsova V. I. Grebennikov N. V. Mushnikov E. G. Gerasimov A. Buling C. Derks M. Neumann 《Bulletin of the Russian Academy of Sciences: Physics》2013,77(2):226-229
The electronic structure of the DyNi2Mn x rare-earth (RE) intermetallides whose cubic structure is similar to the structure of RT2 compounds is studied. Resonant photoemission and X-ray absorption methods are used in the vicinity of the 2p- and 3p-excitation thresholds of transition elements and the 3p-, 3d-, and 4d-thresholds of RE metals to find the Ni, Mn 3d-, and R 4f-partial densities of the states in the valent band. The use of resonant photoemission allows us to establish features of the interaction between the unfinished 4f-shells of ions of RE metals with ions of the transition 3d-elements in RNi2Mn x compounds. The contributions from atoms of various elements to the structure of the valent band are separated, and the basic regularities of band formation during the introduction of manganese atoms are found. 相似文献
3.
The aim of this study was to measure the shear modulus of the vocal fold in a human hemilarynx, such that the data can be related to direction of applied stress and anatomical context. Dynamic spring rate data were collected using a modified linear skin rheometer using human hemilarynges, and converted to estimated shear modulus via application of a simple shear model. The measurement probe was attached to the epithelial layer of the vocal fold cover using suction. A sinusoidal force of 3g was applied to the epithelium, and the resultant displacement logged at a rate of 1kHz. Force measurement accuracy was 20microg and position measurement accuracy was 4microm. The force was applied in a transverse direction at the midmembranous point between the vocal process and the anterior commissure. The shear modulus of the three female vocal folds ranged from 814 to 1232Pa. The shear modulus of the three male vocal folds ranged from 1021 to 1796Pa. These data demonstrate that it is possible to obtain estimates for the shear modulus of the vocal fold while preserving anatomical context. The modulus values reported here are higher than those reported using parallel plate rheometry. This is to be expected as the tissue is attached to surrounding structures, and is under natural tension. 相似文献
4.
N. V. Mushnikov E. G. Gerasimov V. S. Gaviko P. B. Terent’ev K. A. Yazovskikh A. N. Pirogov 《Physics of the Solid State》2018,60(6):1082-1089
The magnetic structures that form in La1–xRxMn2Si2 (R = Sm, Tb) layered compounds with various concentrations x have been determined by magnetic neutron diffraction and magnetic measurements, and the magnetic phase diagrams have been built. It is shown that the formation of the magnetic structures is dependent not only on exchange interactions, but also on the type of the magnetic anisotropy of a rare-earth atom. It is found that, in La1–xTbxMn2Si2 compounds with 0.2 < x < 0.5, the competition of the Tb–Mn and Mn–Mn interlayer exchange interactions and the existence of a strong uniaxial magnetic anisotropy in the Mn and Tb sublattices leads to the frustrated magnetic state and prevents the formation of the long-range magnetic order in the Tb sublattice. 相似文献
5.
N. V. Selezneva N. V. Baranov V. G. Pleshchev N. V. Mushnikov V. I. Maksimov 《Physics of the Solid State》2011,53(2):329-336
The Fe0.5TiSe2 compound with a monoclinic crystal structure has been prepared by intercalation of Fe atoms between Se-Ti-Se sandwiches in the layered structure of TiSe2. The crystal and magnetic structures, electrical resistivity, and magnetization of the Fe0.5TiSe2 compound have been investigated. According to the neutron diffraction data, the Fe0.5TiSe2 compound has a tilted antiferromagnetic structure at temperatures below the Néel temperature of 135 K, in which the magnetic moments of Fe atoms are antiferromagnetically ordered inside layers and located at an angle of approximately 74.4° with respect to the layer plane. The magnetic moment of Fe atoms is equal to (2.98 ± 0.05)μB. The antiferromagnetic ordering is accompanied by anisotropic spontaneous magnetostrictive distortions of the crystal lattice, which is associated with the spin-orbit interaction and the effect of the crystal field. 相似文献
6.
V. V. Serikov N. M. Kleinerman A. V. Vershinin V. S. Gaviko N. V. Mushnikov 《Physics of the Solid State》2013,55(3):495-501
X-ray diffraction patterns and nuclear gamma resonance spectra of La(Fe0.88Si x Al0.12 ? x )13 compounds in the paramagnetic state at room temperature have been investigated. It has been found that all samples have a cubic structure of the NaZn13 type, in which Si and Al atoms disorderly substitute for iron in the crystallographic position 96i. An analysis of the Mössbauer spectra using the fitting with doublets with different quadrupole splittings has revealed that the distributions of the aluminum and silicon impurity atoms substituting for iron differ significantly. Aluminum is statistically distributed over nine positions of the 96i type in the generalized coordination sphere of the Fe2 atom, whereas silicon predominantly substitutes for only six of the nine positions. 相似文献
7.
N. N. Loshkareva N. V. Mushnikov A. V. Korolev A. M. Balbashov 《Physics of the Solid State》2009,51(4):773-777
Studies of the magnetization curves of electron-doped single-crystal manganites Ca1 ? x Ln x MnO3 (Ln = La3+, Ce4+; x ≤ 0.12) in strong pulsed magnetic fields of up to 350 kOe have revealed a metamagnetic transition in Ca0.9Ce0.1MnO3 in the temperature range 77–190 K. The critical transition fields increase to ~350 kOe with the temperature decreasing to 100 K. The spin polarization is ~50% of the theoretical value. These results are interpreted as due to “melting” of the orbital/charge ordering below the temperature T OO/CO = 185 K = T N (of the C type AFM phase); this entails a decrease in the volume of the ordered phase with localized carriers and an increase in the volume of the ferromagnetic phase with delocalized carriers. The temperature and field dependences of the magnetization are used to compare two manganite systems in the region of the two-phase magnetic state. 相似文献
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9.
A.G. Kuchin N.V. Mushnikov M.I. Bartashevich O. Prokhnenko V.I. Khrabrov T.P. Lapina 《Journal of magnetism and magnetic materials》2007
Magnetic properties of the Ce2Fe17−xMnx, x=0–2, alloys in magnetic fields up to 40 T are reported. The compounds with x=0.5–1 are helical antiferromagnets and those with 1<x?2 are helical ferromagnets or helical antiferromagnets at low and high T, respectively. Mn ions in the system carry average magnetic moment of 3.0±0.2 μB that couple antiparallelly to the Fe moments. Easy-plane magnetic anisotropy in the Ce2Fe17−xMnx compounds weakens upon substitution of Mn for Fe. The absolute value of the first anisotropy constant in the Ce2Fe17−xMnx helical ferromagnets decreases slower with increasing temperature than that calculated from the third power of the spontaneous magnetization. Noticeable magnetic hysteresis in the Ce2Fe17−xMnx, x=0.5–2, helical magnets over the whole range of magnetic fields reflects mainly irreversible deformation of the helical magnetic structure during the magnetization of the compounds. A contribution from short-range order (SRO) magnetic clusters to the magnetic hysteresis of the helical magnets has been also estimated. 相似文献
10.
Kurbakov A. I. Korshunov A. N. Pirogov A. N. Gerasimov E. G. Mushnikov N. V. 《Crystallography Reports》2021,66(2):267-280
Crystallography Reports - This study is devoted to magnetic neutron diffraction analysis (elastic neutron scattering yielding information about spin ordering in magnetic materials). Experimental... 相似文献