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Related papers: Charge Order in NaV2O5 studied by EPR

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We show that the proposed zig--zag charge--ordering model for alpha'--NaV2O5 is incompatible with a single transition that induces both charge--ordering and spin gap. We introduce a two--band model for alpha'--NaV2O5 within which the…

Strongly Correlated Electrons · Physics 2007-05-23 R. T. Clay , S. Mazumdar

Neutron diffraction measurements on multiferroic LuFe2O4 show changes in the antiferromagnetic (AFM) structure characterized by wavevector q = (1/3 1/3 1/2) as a function of electric field cooling procedures. The increase of intensity from…

Strongly Correlated Electrons · Physics 2011-11-09 A. M. Mulders , M. Bartkowiak , J. R. Hester , E. Pomjakushina , K. Conder

Measurements of the electrical and thermal conductivities, thermopower and paramagnetic susceptibility have been performed on single crystal samples of Bi1/2Sr1/2MnO3 and complemented with the X-ray powder diffraction data. A pronounced…

Strongly Correlated Electrons · Physics 2009-11-07 J. Hejtmanek , K. Knizek , Z. Jirak , M. Hervieu , C. Martin , M. Nevriva , P. Beran

A possible ground state of NaV_2O_5 is proposed based on the Hartree approximation for both on-site and intersite Coulomb interactions. The results indicate that the intersite Coulomb interaction induces a zigzag type of charge…

Strongly Correlated Electrons · Physics 2009-10-31 Hitoshi Seo , Hidetoshi Fukuyama

We have used rotational anisotropic polarized Raman spectroscopy to study the symmetries, the temperature and the doping dependence of the charge ordered state in metallic $(Sr_{1-x}La_{x})_{3}Ir_{2}O_{7}$. Although the Raman probe size is…

We study the extended Hubbard model with both on-site and nearest neighbor Coulomb repulsion ($U$ and $V$, respectively) in the Dynamical Mean Field theory. At quarter filling, the model shows a transition to a charge ordered phase with…

Strongly Correlated Electrons · Physics 2009-10-31 R. Pietig , R. Bulla , S. Blawid

The I-Mn-V antiferromagnet, NaMnBi, develops a very large positive magnetoresistance (MR) up to 10,000% at 2 K and 9 T in crystals showing a semiconductor-to-metal transition (SMT). In the absence of an SMT, a modest (20%) MR is achieved.…

Materials Science · Physics 2020-07-15 Aaron Wegner , Despina Louca , Keith Taddei , Joerg Neuefeind

Quantum Monte Carlo and density-matrix renormalization group methods are used to study the coupled spin-pseudospin Hamiltonian in one-dimension (1D) that models the charge-ordering instability of the anisotropic Hubbard ladder at quarter…

Strongly Correlated Electrons · Physics 2009-11-11 Y. Ohta , T. Nakaegawa , S. Ejima

Observation of charge ordering in single crystalline and bulk polycrystalline systems of various rare-earth based manganites is well documented. However, there is hardly any manifestation of the same when the grain size is reduced to…

Materials Science · Physics 2009-11-11 Anis Biswas , I. Das

The magnetic and transport properties are systematically studied on the single crystal $Na_{0.55}CoO_2$ with charge ordering and divergency in resistivity below 50 K. A long-range ferromagnetic ordering is observed in susceptibility below…

Strongly Correlated Electrons · Physics 2009-11-11 C. H. Wang , X. H. Chen , T. Wu , X. G. Luo , G. Y. Wang , J. L. Luo

First, second and third nearest neighbor pair mixing potentials for equiatomic FePt alloys were calculated from first principles by the Connolly-Williams method within the canonical cluster expansion formalism. Using the mixing potentials…

Materials Science · Physics 2009-04-23 R. V. Chepulskii , W. H. Butler

The temperature dependence of charge order in Fe2OBO3 was investigated by resistivity and differential scanning calorimetry measurements, Mossbauer spectroscopy, and synchrotron x-ray scattering, revealing an intermediate phase between room…

Strongly Correlated Electrons · Physics 2007-12-19 M. Angst , R. P. Hermann , W. Schweika , J. -W. Kim , P. Khalifah , H. J. Xiang , M. -H. Whangbo , D. -H. Kim , B. C. Sales , D. Mandrus

Recent X-ray analysis and NMR- experiments have shown that alpha'- NaV2O5 is not a conventional spin-Peierls (SP) compound because above the transition at 33K it is in a homogeneous mixed valent (MV) state and atomic spin chains do not…

Strongly Correlated Electrons · Physics 2009-10-31 P. Thalmeier , P. Fulde

Data taken by various kinds of methods including NMR/NQR and neutron scattering are presented for NaxCoO2, in particular, for Na0.5CoO2. Attentions have also been paid to the x dependence of the electronic nature. The pseudo-gap-like…

Strongly Correlated Electrons · Physics 2009-11-11 Mai Yokoi , Taketo Moyoshi , Yoshiaki Kobayashi , Minoru Soda , Yukio Yasui , Masatoshi Sato , Kazuhisa Kakurai

Using one- and two-dimensional NMR spectroscopy applied to $^{13}$C spin-labeled (TMTTF)$_2$AsF$_6$ and (TMTTF)$_2$PF$_6$, we demonstrate the existence of an intermediate charge-ordered phase in the TMTTF family of charge-transfer salts. At…

Strongly Correlated Electrons · Physics 2009-10-31 D. S. Chow , F. Zamborszky , B. Alavi , D. J. Tantillo , A. Baur , C. A. Merlic , S. E. Brown

We present a scenario for the peculiar coexistence of charge fluctuations observed in quasi-2D 1/4-filled organic conductors $\theta$-(BEDT-TTF)$_2X$ in the quantum critical regime where the charge ordering is suppressed down to zero…

Strongly Correlated Electrons · Physics 2009-11-13 Masafumi Udagawa , Yukitoshi Motome

We present the results of a systematic x-ray scattering study of the charge and orbital ordering in the manganite series Pr$_{1-x}$Ca$_x$MnO$_3$ with $x$=0.25, 0.4 and 0.5. The temperature dependence of the scattering at the charge and…

Strongly Correlated Electrons · Physics 2009-10-31 M. v. Zimmermann , C. S. Nelson , J. P. Hill , Doon Gibbs , M. Blume , D. Casa , B. Keimer , Y. Murakami , C. -C. Kao , C. Venkataraman , T. Gog , Y. Tomioka , Y. Tokura

The specific heat, magnetic susceptibility and ESR signals of a Na-deficient vanadate Na_xV_2O_5 (x=1.00 - 0.90) were studied in the temperature range 0.07 - 10 K, well below the transition point to a spin-gap state. The contribution of…

Strongly Correlated Electrons · Physics 2009-10-31 A. I. Smirnov , S. S. Sosin , R. Calemczuk , V. Villar , C. Paulsen , M. Isobe , Y. Ueda

Co and Na NMR are used to probe the local susceptibility and charge state of the two Co sites of the Na-ordered orthorhombic Na0.5CoO2. Above T_N=86K, both sites display a similar T-dependence of the spin shift, suggesting that there is no…

Strongly Correlated Electrons · Physics 2009-11-11 J. Bobroff , G. Lang , H. Alloul , N. Blanchard , G. Collin

The temperature dependence of the integrated optical conductivity I(T) reflects the changes of the kinetic energy as spin and charge correlations develop. It provides a unique way to explore experimentally the kinetic properties of strongly…

Strongly Correlated Electrons · Physics 2009-11-07 Markus Aichhorn , Peter Horsch , Wolfgang von der Linden , Mario Cuoco
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