排序方式: 共有76条查询结果,搜索用时 15 毫秒
1.
S. Paschen M. Müller J. Custers M. Kriegisch A. Prokofiev G. Hilscher W. Steiner A. Pikul F. Steglich A.M. Strydom 《Journal of magnetism and magnetic materials》2007
The cage compound Ce3Pd20Si6 has recently been shown to undergo two successive low-temperature phase transitions which are strongly affected by an applied magnetic field. Here we show that, as the lower, probably antiferromagnetic transition is suppressed to zero in a field slightly above 1 T, the electrical resistivity shows a non-Fermi-liquid-like linear-in-T temperature dependence while it follows the usual Fermi liquid T2 temperature dependence both at smaller and larger fields. This suggests that a field-induced quantum critical point exists in Ce3Pd20Si6. 相似文献
2.
G. D. Alkhazov A. N. Prokofiev I. B. Smirnov E. A. Strokovsky 《Physics of Atomic Nuclei》2012,75(9):1067-1076
An analysis of the experimental data on one-pion and two-pion production in the p(??, ????)X reaction studied in a semi-exclusive experiment at an energy of E ?? = 4.2 GeV has been performed. The obtained results demonstrate that the inelastic ??-particle scattering on the proton at the energy of the experiment proceeds either through excitation and decay of the ?? resonance in the projectile ?? particle, or through excitation in the target proton of the Roper resonance, which decays into a nucleon and a pion, or a nucleon and a ?? meson??a system of two pions in the isospin I = 0, S-wave state. 相似文献
3.
Prokofiev A. A. Moskalenko A. S. Yassievich I. N. de Boer W. D. A. M. Timmerman D. Zhang H. Buma W. J. Gregorkiewicz T. 《JETP Letters》2010,90(12):758-762
JETP Letters - The effect of quantum confinement on the direct bandgap of spherical Si nanocrystals has been modelled theoretically. We conclude that the energy of the direct bandgap at the... 相似文献
4.
M. A. Odnoblyudov A. A. Prokofiev I. N. Yassievich 《Journal of Experimental and Theoretical Physics》2002,94(3):593-602
A new approach to calculating the parameters of resonant states is proposed, which also makes it possible to determine the probabilities of the resonant scattering and capture probabilities at the resonant state. This approach is based on the application of the method of configuration interaction, which was proposed for the first time by Fano for an analysis of field ionization of the helium atom. Following Fano, use is made of two different Hamiltonians of the initial approximation for the states of continuum and the initial local state. Following Dirac, the wave functions are constructed in the same way as in the general theory of scattering. A detailed analysis and specific calculations are made for resonant acceptor states in uniaxially strained germanium under a pressure directed along the [001] and [111] axes. 相似文献
5.
We construct the theory of carriers confined in Si quantum dots with finite energy barriers for electrons and holes in the framework of the multiband effective mass theory. We apply this theory for theoretical modeling of the excitation of erbium inside and outside of Si nanocrystals in SiO2 matrix due to the Auger process induced by the recombination of a confined electron-hole pair as well as the intraband transitions of “hot” confined carriers. Auger de-excitation processes of the Er3+ ion leading to the quenching of erbium luminescence are discussed as well. 相似文献
6.
A.V. Prokofiev F. Büllesfeld W. Assmus H. Schwenk D. Wichert U. Löw B. Lüthi 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,5(3):313-316
Experimental results on magnetic resonance (ESR) and magnetic susceptibility are given for single crystalline (VO)2P2O7. The crystal growth procedure is briefly discussed. The susceptibility is interpreted numerically using a model with alternating
spin chains. We determine J
=51 K and . Furthermore we find a spin gap of meV from our ESR measurements. Using elastic constants no indication of a phase transition forcing the dimerization is seen
below 300 K.
Received: 22 December 1997 / Accepted: 17 March 1998 相似文献
7.
Semiexclusive measurements of the two-pion production reaction p(α, α′)pππ have been carried out at an energy of E
α
= 4.2 GeV at the Saturne-II (Saclay) accelerator with the SPES4-π installation. The two-pion production reaction was investigated by simultaneous registration of the scattered α particle and the secondary proton. The obtained results show that the two-pion decay of the P
11(1440) resonance excited in the target proton in this reaction proceeds predominantly with emission of two pions in the isospin
I = 0, S-wave state.
The text was submitted by the authors in English.
the SPES4-π Collaboration 相似文献
8.
I. S. Veshchunov V. A. Oboznov A. N. Rossolenko A. S. Prokofiev L. Ya. Vinnikov A. Yu. Rusanov D. V. Matveev 《JETP Letters》2008,88(11):758-761
We report on the first experimental visualization of domain structure in films of weakly ferromagnetic Cu0.47Ni0.53 alloy with different thickness at liquid helium temperatures. Improved high-resolution Bitter decoration technique was used
to map the magnetic contrast on the surface of the films well below the Curie temperature TCurie (∼60 K). In contrast to magnetic force microscopy, this technique allowed visualization of the domain structure without its
disturbance while the larger areas of the sample were probed. Maze-like domain patterns, typical for perpendicular magnetic
anisotropy, were observed. The average domain width was found to be about 100 nm.
The article is published in the original. 相似文献
9.
N. N. Kuranova V. V. Makarov V. G. Pushin A. N. Uksusnikov R. Z. Valiev D. V. Gunderov A. V. Lukyanov E. A. Prokofiev 《Bulletin of the Russian Academy of Sciences: Physics》2009,73(8):1117-1119
The structure of bulk samples of Ti49.4Ni50.6 alloy after severe plastic deformation by torsion (SPDT) under high pressure have been studied by transmission and scanning
electron microscopies. It is found that SPDT by five to seven turns led to almost complete alloy amorphization. 相似文献
10.
Stefan Laumann Matthias Ikeda Herbert Sassik Andrey Prokofiev Prof. Dr. Silke Paschen 《无机化学与普通化学杂志》2012,638(2):294-301
Intermetallic clathrates are promising materials for thermoelectric applications. This is not only due to their low thermal and high electrical conductivities (“phonon glass – electron crystal”) but also due to the expectation that they are semiconductors and thus have large thermopower values. Band structure calculations of the stoichiometric compound Eu8Ga16Ge30 indeed yield a semiconducting ground state. However, with conventional synthesis methods the exact 8:16:30 stoichiometry could not be reached. Herein we use the melt‐spinning technique to obtain Eu8Ga16–xGe30+x samples with smaller x than previously realized. The quenching procedure and the results of the characterization of the quenched phases by X‐ray powder diffraction and electron microscopy are presented. The electrical resistivity shows that, in contrast to conventional synthesis procedures, semiconducting compounds can be produced. 相似文献