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Related papers: Three-Dimensional Spin Fluctuations in Na0.75CoO2

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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

We report ^{59}Co NMR studies in single crystals of cobalt oxide superconductor Na_{0.42}CoO_{2}\cdot1.3H_{2}O (T_c=4.25K) and its parent compound Na_{0.42}CoO_{2}. We find that both the magnitude and the temperature (T) dependence of the…

Superconductivity · Physics 2009-11-13 K. Matano , C. T. Lin , Guo-qing Zheng

Nuclear-magnetic-resonance (NMR) studies were performed in Na$_{0.7}$CoO$_2$ to investigate its magnetic properties from the microscopic point of view. Na$_{0.7}$CoO$_2$ is a starting compound of the recently discovered superconductor…

Strongly Correlated Electrons · Physics 2009-11-10 Y. Ihara , K. Ishida , C. Michioka , M. Kato , K. Yoshimura , H. Sakurai , E. Takayama-Muromachi

Inelastic neutron scattering measurements mapping the in-plane magnetic interactions of Na0.5CoO2 reveal dispersive excitations at points above an energy gap Eg = 11.5(5) meV at the superstructural Bragg reflections. The excitations are…

Strongly Correlated Electrons · Physics 2007-05-23 J. Wooldridge , G. Balakrishnan , D. McK. Paul , C. Frost , P. Bourges , M. R. Lees

Na$_x$CoO$_2$, the parent compound of the recently synthesized superconductor Na$_x$CoO$_2$:$y$H$_2$O, exhibits bulk antiferromagnetic order below $\sim20$ K for 0.75 $\leq x \leq$ 0.9. We have performed neutron scattering experiments in…

Strongly Correlated Electrons · Physics 2009-11-10 S. P. Bayrakci , I. Mirebeau , P. Bourges , Y. Sidis , M. Enderle , J. Mesot , D. P. Chen , C. T. Lin , B. Keimer

We study the interplay between superconductivity and antiferromagnetic spin fluctuations in electron-doped cobaltate Na$_{x}$CoO$_{2}\cdot y$H$_{2}$O based on the kinetic energy driven superconductivity mechanism. We show that the…

Strongly Correlated Electrons · Physics 2015-06-12 Ying Liang , Bin Liu

Spin and charge fluctuations and superconductivity in Na_0.35CoO_2*1.3H_2O are studied based on a multi-orbital Hubbard model. By applying the fluctuation exchange (FLEX) approximation, we show that the Hund's-rule coupling between the Co…

Strongly Correlated Electrons · Physics 2007-05-23 Masahito Mochizuki , Youichi Yanase , Masao Ogata

We report the first observation of two-dimensional incommensurate magnetic fluctuations in the layered metallic perovskite Sr3Ru2O7. The wavevectors where the magnetic fluctuations are strongest are different from those observed in the…

Strongly Correlated Electrons · Physics 2007-05-23 L. Capogna , E. M. Forgan , S. M. Hayden , A. Wildes , J. A. Duffy , A. P. Mackenzie , R. S. Perry , S. Ikeda , Y. Maeno , S. P. Brown

We describe neutron scattering experiments performed to investigate the magnetic order and dynamics of half-doped La1.5Sr0.5CoO4. This layered perovskite exhibits a near-ideal checkerboard pattern of Co2+/Co3+ charge order at temperatures…

Strongly Correlated Electrons · Physics 2009-10-19 L. M. Helme , A. T. Boothroyd , R. Coldea , D. Prabhakaran , C. D. Frost , D. A. Keen , L. P. Regnault , P. G. Freeman , M. Enderle , J. Kulda

We report a combination of physical property and neutron scattering measurements for polycrystalline samples of the one-dimensional spin chain compound CoV2O6. Heat capacity measurements show that an effective S = 1/2 state is found at low…

Magnetism of layered cobaltites Na$_x$CoO$_2$ with $x$ = 0.6 and 0.9 has been investigated by a positive muon spin rotation and relaxation ($\mu^+$SR) spectroscopy together with magnetic susceptibility and specific heat measurements, using…

Strongly Correlated Electrons · Physics 2009-11-10 J. Sugiyama , J. H. Brewer , E. J. Ansaldo , B. Hitti , M. Mikami , Y. Mori , T. Sasaki

We report magnetization, specific heat, muon spin rotation and Na NMR measurements on the S=3/2 rhombohedrally stacked Heisenberg antiferromagnet NaCrO2. This compound appears to be an ideal candidate for the study of triangular Heisenberg…

Strongly Correlated Electrons · Physics 2007-05-23 A. Olariu , P. Mendels , F. Bert , B. G. Ueland , P. Schiffer , R. F. Berger , R. J. Cava

Inelastic neutron scattering measurements on single crystals of superconducting BaFe1.84Co0.16As2 reveal a magnetic excitation located at wavevectors (1/2 1/2 L) in tetragonal notation. On cooling below TC, a clear resonance peak is…

We have observed a diffuse component to the low-energy magnetic excitation spectrum of stripe-ordered La5/3Sr1/3NiO4 probed by neutron inelastic scattering. The diffuse scattering forms a square pattern with sides parallel and perpendicular…

Strongly Correlated Electrons · Physics 2009-11-10 A. T. Boothroyd , P. G. Freeman , D. Prabhakaran , A. Hiess , M. Enderle , J. Kulda , F. Altorfer

Here we report an unconventional magnetic and transport phenomenon in a layered cobalt oxide, NaxCoO2. Only for x = 0.75, a magnetic transition of the second order was clearly detected at Tm ~ 22 K where an apparent specific-heat jump, an…

Strongly Correlated Electrons · Physics 2009-11-07 T. Motohashi , R. Ueda , E. Naujalis , T. Tojo , I. Terasaki , T. Atake , M. Karppinen , H. Yamauchi

We present an X-ray diffuse scattering study of the pretransitional structural fluctuations of the magneto-elastic transition in alpha'-NaV2O5. This transition is characterized by the appearance below Tsp~35K of satellite reflections at the…

Strongly Correlated Electrons · Physics 2009-10-31 S. Ravy , J. Jegoudez , A. Revcolevschi

Polarized neutron inelastic scattering has been used to measure spin excitations in ferromagnetic La$_{0.82}$Sr$_{0.18}$CoO$_{3}$. The magnon spectrum of these spin excitations is well defined at low energies but becomes heavily damped at…

Strongly Correlated Electrons · Physics 2010-10-08 R. A. Ewings , P. G. Freeman , M. Enderle , J. Kulda , D. Prabhakaran , A. T. Boothroyd

Magnetic fluctuations in the molecular-intercalated FeSe superconductor Li{x}(ND2){y}(ND3){1-y}Fe2Se2 (Tc = 43K) have been measured by inelastic neutron scattering from a powder sample. The strongest magnetic scattering is observed at a…

We report polarized- and unpolarized- neutron inelastic scattering measurements of the magnetic excitation spectrum in the spin-charge ordered phase of La3/2Sr1/2NiO4. Up to energies of ~30 meV we observe broad magnetic modes characteristic…

Strongly Correlated Electrons · Physics 2009-11-10 P. G. Freeman , A. T. Boothroyd , D. Prabhakaran , C. Frost , M. Enderle , A. Hiess
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