413 research outputs found
Anisotropic Exchange in
We investigate the magnetic properties of the multiferroic quantum-spin
system LiCuO by electron spin resonance (ESR) measurements at - and
-band frequencies in a wide temperature range \,K). The observed anisotropies of the tensor and the ESR linewidth in
untwinned single crystals result from the crystal-electric field and from local
exchange geometries acting on the magnetic Cu ions in the zigzag-ladder
like structure of LiCuO. Supported by a microscopic analysis of the
exchange paths involved, we show that both the symmetric anisotropic exchange
interaction and the antisymmetric Dzyaloshinskii-Moriya interaction provide the
dominant spin-spin relaxation channels in this material.Comment: 10 pages, 10 Figure
Pension System as Wellbeing Institute
The article proves that it is possible to achieve wellbeing if there is an improvement of both the pension system and change in the citizen’s attitude towards retirement income. The calculations (dynamics of the percentage of the working retirees, both in Russia and TPU, and the average salary) show that the increase in the ratio of the number of retirees and working people can’t lead to the deficit of the budget of the Russian Pension Fund. It is proved that the key way to overcome the deficit is to remove payments, which are not or little connected with earned income (disability and loss of a breadwinner pension, long service pension, and early retirement pension) and save only one function – compensation for loss of earnings. Refusal of the territorial rent (pension’s peg to the minimum of subsistence of a retiree in the region) will also balance the financial state of the Pension Fund. It is mathematically proved that the wellbeing of retirees can be reached if they participate in the compulsory and voluntary pension insurance programs, which are not necessary governmental
Anisotropic Exchange in LiCuVO probed by ESR
We investigated the paramagnetic resonance in single crystals of LiCuVO
with special attention to the angular variation of the absorption spectrum. To
explain the large resonance linewidth of the order of 1 kOe, we analyzed the
anisotropic exchange interaction in the chains of edge-sharing CuO
octahedra, taking into account the ring-exchange geometry of the
nearest-neighbor coupling via two symmetric rectangular Cu-O bonds. The
exchange parameters, which can be estimated from theoretical considerations,
nicely agree with the parameters obtained from the angular dependence of the
linewidth. The anisotropy of this magnetic ring exchange is found to be much
larger than it is usually expected from conventional estimations which neglect
the bonding geometry. Hence, the data yield the evidence that in copper oxides
with edge-sharing structures the role of the orbital degrees of freedom is
strongly enhanced. These findings establish LiCuVO as one-dimensional
compound at high temperatures.
PACS: 76.30.-v, 76.30.Fc, 75.30.EtComment: 18 pages, 6 figure
Experimental study of chemiluminescence in UV and VIS range at hydrogen-oxygen mixtures ignition
Pedagogical dialogue: cognitive strategies of philological education in Russia and abroad
The article presents an overview of an International scientific and pedagogical forum "The Image of Russia in global educational space: language, history, culture", which was held on May 23-26 2019 at Ural State Pedagogical University (Russia, Yekaterinburg) and Jilin University of international studies (China, Changchun).В статье представлен обзор Международного научно-педагогического форума "Образ России в глобальном образовательном пространстве: язык, история, культура", который был проведен с 23 по 26 мая 2019 года в Уральском государственном педагогическом университете (Россия, Екатеринбург) и Цзилиньском университете международных исследований (Китай, Чанчунь)
Electron spin resonance and exchange paths in the orthorhombic dimer system Sr2VO4
We report on magnetization and electron spin resonance (ESR) measurements of
SrVO with orthorhombic symmetry. In this dimer system the
ions are in tetrahedral environment and are coupled by an antiferromagnetic
intra-dimer exchange constant 100 K to form a singlet ground
state without any phase transitions between room temperature and 2 K. Based on
an extended-H\"{u}ckel-Tight-Binding analysis we identify the strongest
exchange interaction to occur between two inequivalent vanadium sites via two
intermediate oxygen ions. The ESR absorption spectra can be well described by a
single Lorentzian line with an effective g-factor = 1.89. The temperature
dependence of the ESR intensity is well described by a dimer model in agreement
with the magnetization data. The temperature dependence of the ESR linewidth
can be modeled by a superposition of a linear increase with temperature with a
slope = 1.35 Oe/K and a thermally activated behavior with an
activation energy = 1418 K, both of which point to spin-phonon
coupling as the dominant relaxation mechanism in this compound.Comment: 5 pages, 4 figure
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