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Related papers: Low-energy excitations in NaV2O5

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We have performed quasielastic and inelastic neutron scattering (QENS and INS) measurements from 300 K to 1173 K to investigate the Na-diffusion and underlying host dynamics in Na2Ti3O7. The QENS data show that the Na atoms undergo…

The alterations in the magnetic properties and electronic structure of chemical vapor deposition (CVD) grown nano-dimensional molybdenum disulfide (MoS2) after low energy ion irradiation are thoroughly investigated. The formation of pure…

To elucidate the low-energy excitation spectrum of correlated electrons on a 2D triangular lattice, we have studied the electrical resistance and specific heat down to 0.5 K and in magnetic fields up to 14 T, in NaxCoO2 samples with a Na…

Strongly Correlated Electrons · Physics 2009-11-11 M. Brühwiler , B. Batlogg , S. M. Kazakov , Ch. Niedermayer , J. Karpinski

Transmission electron microscopy observations reveal the presence of complex superstructures and remarkable phase separation in association with Na-ordering phenomenon in y-Na0.5CoO2. Resistivity and magnetization measurements indicate that…

Strongly Correlated Electrons · Physics 2007-05-23 H. X. Yang , Y. G. Shi , C. J. Nie , D. Wu , L. X. Yang , C. Dong , H. C. Yu , H. R. Zhang , C. Q. Jin , J. Q. Li

The magnetic behaviour of the low-dimensional Vanadium-oxides Sr2V3O9 and Ba2V3O9 was investigated by means of magnetic susceptibility and specific heat measurements. In both compounds, the results can be very well described by an S=1/2…

Condensed Matter · Physics 2009-11-07 E. E. Kaul , H. Rosner , V. Yushankhai , J. Sichelschmidt , R. V. Shpanchenko , C. Geibel

In order to confirm the picture of domain-wall excitations in the hidden antiferromagnetic order of the Haldane phase, the structure of the low-lying excitations in the S=1 antiferromagnetic Heisenberg chain is studied by a quantum Monte…

Statistical Mechanics · Physics 2009-10-30 Shoji Yamamoto , Seiji Miyashita

Effect of the femtosecond and nanosecond UV laser irradiation (below the ablation threshold) of graphite-like hexagonal boron nitride (hBN) has been studied. Experiments were carried out with the compacted powder under high vacuum at room…

Magnetic excitations of the quasi-1D S=1/2 Heisenberg antiferromagnet (HAF) Cs2CuCl4 have been measured as a function of magnetic field using neutron scattering. For T<0.62 K and B=0 T the weak inter-chain coupling produces 3D…

Strongly Correlated Electrons · Physics 2009-10-30 R. Coldea , D. A. Tennant , R. A. Cowley , D. F. McMorrow , B. Dorner , Z. Tylczynski

Inelastic light scattering studies on single crystals of (Na$_{1-x}$Li$_x$)$_2$IrO$_3$ ($x = 0, 0.05$ and $0.15$) show a polarization independent broad band at $\sim $~2750 cm$^{-1}$ with a large band-width $\sim 1800$~cm$^{-1}$. For…

We have performed quasielastic neutron scattering (QENS) experiments up to 1243 K and ab-initio molecular dynamics (AIMD) simulations to investigate the Na diffusion in various phases of NaAlSiO4 (NASO), namely, low-carnegieite (L-NASO;…

The effect of surface degradation of the thermolectric cobaltite on Raman spectra is discussed and compared to experimental results from Co3O4 single crystals. We conclude that on NaCl flux grown NaxCoO2 crystals a surface layer of Co3O4…

Strongly Correlated Electrons · Physics 2015-06-25 P. Lemmens , P. Scheib , Y. Krockenberger , L. Alff , F. C. Chou , C. T. Lin , H. -U. Habermeier , B. Keimer

We present neutron scattering spectra taken from a single crystal of Na0.75CoO2, the precursor to a novel cobalt-oxide superconductor. The data contain a prominent inelastic signal at low energies (~10 meV), which is localized in wavevector…

Strongly Correlated Electrons · Physics 2009-11-10 A. T. Boothroyd , R. Coldea , D. A. Tennant , D. Prabhakaran , L. M. Helme , C. D. Frost

We report polarized and unpolarized neutron scattering measurements of the magnetic order in single crystals of Na0.5CoO2. Our data indicate that below T_N=88 K the spins form a novel antiferromagnetic pattern within the CoO2 planes,…

Strongly Correlated Electrons · Physics 2009-11-11 G. Gasparovic , R. A. Ott , J. -H. Cho , F. C. Chou , Y. Chu , J. W. Lynn , Y. S. Lee

Temperature evolution of dielectric response, atomic structure, and lattice dynamics in thin film of sodium niobate in the epitaxial NaNbO$_3$/SrRuO$_3$/(001)MgO heterostructure is studied by dielectric measurements, x-ray diffraction, and…

High-resolution inelastic x-ray scattering measurements were carried out on molten NaI near the melting point at 680$^\circ$C at SPring-8. Small and damped indications of longitudinal optic excitation modes were observed on the tails of the…

Materials Science · Physics 2019-12-05 S. Hosokawa , M. Inui , T. Bryk , I. Mryglod , W. -C. Pilgrim , Y. Kajihara , K. Matsuda , Y. Ohmasa , S. Tsutsui

Raman scattering experiments have been performed on Na_xCoO_2 as function of temperature at the composition x=0.5 where a structural instability and a metal-insulator transition have been observed. Three additional phonon modes are observed…

Strongly Correlated Electrons · Physics 2010-03-09 X. N. Zhang , P. Lemmens , V. Gnezdilov , K. Y. Choi , B. Keimer , D. P. Chen , C. T. Lin , F. C. Chou

The title compound belongs to a wide group of quasi-one-dimensional (Q1D) antiferromagnets (AF) and its Co2+ ions form Q1D screw-chains along the c-axis. We here present the first investigation of the microscopic magnetic nature of a single…

Strongly Correlated Electrons · Physics 2013-07-30 M. Mansson , K. Prsa , J. Sugiyama , H. Nozaki , A. Amato , K. Omura , S. Kimura , M. Hagiwara

Recent experimental evidence suggest the existence of three distinct V-valence states (V^{+4}, V^{+4.5} and V^{+5}) in the low-temperature phase of NaV_2O_5 in apparent discrepancy with the observed spin-gap. We investigate a novel spin…

Condensed Matter · Physics 2009-10-31 Claudius Gros , Roser Valenti , J. V. Alvarez , Kay Hamacher , Wolfgang Wenzel

We measured the resistivity and magnetic susceptibility to map out the phase diagram of single crystalline NaFe$_{1-x}$Co$_x$As. Replacement of Fe by Co suppresses both the structural and magnetic transition, while enhances the…

Superconductivity · Physics 2012-06-21 A. F. Wang , X. G. Luo , Y. J. Yan , J. J. Ying , Z. J. Xiang , G. J. Ye , P. Cheng , Z. Y. Li , W. J. Hu , X. H. Chen

By means of thermal expansion and specific heat measurements on the high-pressure phase of (VO)$_2$P$_2$O$_7$, the effects of two energy scales of the weakly dimerized antiferromagnetic $S$ = 1/2 Heisenberg chain are explored. The low…

Strongly Correlated Electrons · Physics 2011-11-09 A. Brühl , B. Wolf , V. Pashchenko , M. Anton , C. Gross , W. Assmus , R. Valenti , S. Glocke , A. Klümper , T. Saha-Dasgupta , B. Rahaman , M. Lang