5,250 research outputs found
Large non-adiabatic hole polarons and matrix element effects in the angle-resolved photoemission spectroscopy of dielectric cuprates
It has been made an extention of the conventional theory based on the
assumption of the well isolated Zhang-Rice singlet to be a first
electron-removal state in dielectric copper oxide. One assumes the photohole
has been localised on either small (pseudo)Jahn-Teller polaron or large
non-adiabatic polaron enclosed one or four to five centers,
respectively, with active one-center valent
manifold. In the framework of the cluster model we have performed a model
microscopic calculation of the -dependence of the matrix element
effects and photon polarization effects for the angle-resolved photoemission in
dielectric cuprate like . We show that effects like the
''remnant Fermi surface'' detected in ARPES experiment for
may be, in fact, a reflection of the matrix element
effects, not a reflection of the original band-structure Fermi surface, or the
strong antiferromagnetic correlations. The measured dispersion-like features in
the low-energy part of the ARPES spectra may be a manifestation of the complex
momentum-dependent spectral line-shape of the large PJT polaron response, not
the dispersion of the well-isolated Zhang-Rice singlet in antiferromagnetic
matrix.Comment: 16 pages, TeX, 9 eps figures adde
Phase equilibria and thermodynamic properties of oxide systems on the basis of rare earth, alkaline earth and 3d-transition (Mn, Fe, Co) metals. A short overview of
Review is dedicated studies of phase equilibria in the systems based on rare earth elements and 3d transition metals. It’s highlighted several structural families of these compounds and is shown that many were found interesting properties for practical application, such as high conductivity up to the superconducting state, magnetic properties, catalytic activity of the processes of afterburning of exhaust gases, the high mobility in the oxygen sublattice and more
Mass distributions for nuclear disintegration from fission to evaporation
By a proper choice of the excitation energy per nucleon we analyze the mass
distributions of the nuclear fragmentation at various excitation energies.
Starting from low energies (between 0.1 and 1 MeV/nucleon) up to higher
energies about 12 MeV/n, we classified the mass yield characteristics for heavy
nuclei (A>200) on the basis of Statistical Multifragmentation Model. The
evaluation of fragment distribution with the excitation energy show that the
present results exhibit the same trend as the experimental ones.Comment: 5 pages, 3 figure
Bulk Oxygen Diffusion and Surface Exchange Limitations in La2−xSrxNi1-yFeyO4+δ
The oxygen permeation flux through dense La1.2Sr0.8Ni0.9Fe0.1O4
Synthesis, Crystal Structure, and Properties of NdNi0.5Mn0.5O3−
The crystal structure and properties of NdNi0.5Mn0.5O3
Crystal structure, oxygen non-stoichiometry and conductivity of Nd1-xAxMn0.5Fe0.5O3-δ (A=Ca, Sr, Ba)
This work was financially supported by RFBR (project No. 16-53-45010 IND_а)
Parity Inversion And Different Properties of Be11 halo Nuclei
The recent developments of radioactive nuclear beams has opened up the
possibility of exploring a wide variety of nuclei far from the valley of
beta-stability. Of late several theoretical studies have come up in the past
for describing nuclei in these exotic region. Extension of traditional shell
model techniques to explain the exotic feature in the structure of these nuclei
such as, formation of neutron halo large r.m.s radii, soft dipole resonances
etc have confirmed the necessity to modify the single particle shell model
potential when dealing with nuclei far from stability. The ground state nuclear
structure properties of 4Be11 have been calculated in the framework of shell
model using analytically soluble mean field potential given by Ginocchio. The
potential is highly versatile in nature and depends on four parameters, which
define its depth, range and shape. Potential parameters, which generate highly
diffuse shape, account for the small binding and halo structure of the valence
neutron in 4Be11. The problem of ground state parity inversion is also
addressed
Effective moment of inertia for several fission reaction systems induced by nucleons, light particles and heavy ions
Compound nucleus effective moment of inertia has been calculated for several
fission reaction systems induced by nucleons, light particles, and heavy ions.
Determination of this quantity for these systems is based upon the comparison
between the experimental data of the fission fragment angular distributions as
well as the prediction of the standard saddle-point statistical model (SSPSM).
For the systems, the two cases, namely with and without neutron emission
corrections were considered. In these calculations, it is assumed that all the
neutrons are emitted before reaching the saddle point.It should be noted that
the above method for determining of the effective moment of inertia had not
been reported until now and this method is used for the first time to determine
compound nucleus effective moment of inertia. Hence, our calculations are of
particular importance in obtaining this quantity, and have a significant rule
in the field of fission physics. Afterwards, our theoretical results have been
compared with the data obtained from the rotational liquid drop model as well
as the Sierk model, and satisfactory agreements were found. Finally, we have
considered the effective moment of inertia of compound nuclei for the systems
that formed similar compound nuclei at similar excitation energies.Comment: 9 pages, 2 Figures, 2 Table
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