409 research outputs found
Ac Susceptibility and Static Magnetization Measurements of CeRuSi at Small Magnetic Fields and Ultra Low Temperatures
The magnetic properties of CeRuSi at microkelvin temperatures (down
to 170 K) and ultra small magnetic fields ( mT) are
investigated experimentally for the first time. The simultaneously measured ac
susceptibility and static magnetization show neither evidence of the magnetic
ordering, superconductivity down to the lowest temperatures nor conventional
Landau Fermi-Liquid behavior. The results imply the magnetic transition
temperature in undoped CeRuSi is very close to absolute 0 K. The
possibility for proximity of CeRuSi to the quantum critical point
without any doping is discussed.Comment: 4 pages, 3 figures; accepted for publication in Phys. Rev. B (Rapid
Communication) and scheduled issue on 1st of May 200
Electronic properties of LaAlO3/SrTiO3 n-type interfaces: A GGA+U study
The role of electronic correlation effects for a realistic description of the
electronic properties of LaAlO3/SrTiO3 heterostructures as covered by the
on-site Coulomb repulsion within the GGA+U approach is investigated. Performing
a systematic variation of the values of the Coulomb parameters applied to the
Ti 3d and La 4f orbitals we put previous suggestions to include a large value
for the La 4f states into perspective. Furthermore, our calculations provide
deeper insight into the band gap landscape in the space spanned by these
Coulomb parameters and the resulting complex interference effects. In addition,
we identify important correlations between the local Coulomb interaction within
the La 4f shell, the band gap, and the atomic displacements at the interface.
In particular, these on-site Coulomb interactions influence buckling within the
LaO interface layer, which via its strong coupling to the electrostatic
potential in the LAO overlayer causes considerable shifts of the electronic
states at the surface and eventually controls the band gap.Comment: 14 pages, 9 figure
On the hyperfine interaction in rare-earth Van Vleck paramagnets at high magnetic fields
An influence of high magnetic fields on hyperfine interaction in the
rare-earth ions with non-magnetic ground state (Van Vleck ions) is
theoretically investigated for the case of ion in axial symmetrical
crystal electric field (ethylsulphate crystal). It is shown that magnetic-field
induced distortions of -electron shell lead to essential changes in
hyperfine magnetic field at the nucleus. The proposed theoretical model is in
agreement with recent experimental data.Comment: 4 pages, no figures, submitted to J. Phys. : Cond. Mat
Phenomenological model of relaxor behavior
© 2016, Allerton Press, Inc.A phenomenological model is proposed for describing the behavior of ferroelectrics with the diffuse phase transition near the permittivity maximum in the low-temperature phase. The behavior in this temperature range is shown to be related to the dynamics of formation of polarized state regions near defects with localized charges. The delay in the transition to the uniformly polarized state in the low-temperature phase is discussed
Phenomenological model of relaxor behavior
© 2016, Allerton Press, Inc.A phenomenological model is proposed for describing the behavior of ferroelectrics with the diffuse phase transition near the permittivity maximum in the low-temperature phase. The behavior in this temperature range is shown to be related to the dynamics of formation of polarized state regions near defects with localized charges. The delay in the transition to the uniformly polarized state in the low-temperature phase is discussed
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