26,006 research outputs found

    Evidence for spin-flip scattering and local moments in dilute fluorinated graphene

    Full text link
    The issue of whether local magnetic moments can be formed by introducing adatoms into graphene is of intense research interest because it opens the window to fundamental studies of magnetism in graphene, as well as of its potential spintronics applications. To investigate this question we measure, by exploiting the well-established weak localization physics, the phase coherence length L_phi in dilute fluorinated graphene. L_phi reveals an unusual saturation below ~ 10 K, which cannot be explained by non-magnetic origins. The corresponding phase breaking rate increases with decreasing carrier density and increases with increasing fluorine density. These results provide strong evidence for spin-flip scattering and points to the existence of adatom-induced local magnetic moment in fluorinated graphene. Our results will stimulate further investigations of magnetism and spintronics applications in adatom-engineered graphene.Comment: 9 pages, 4 figures, and supplementary materials; Phys. Rev. Lett. in pres

    Isospin breaking and f0(980)f_0(980)-a0(980)a_0(980) mixing in the η(1405)π0f0(980)\eta(1405) \to \pi^{0} f_0(980) reaction

    Get PDF
    We make a theoretical study of the η(1405)π0f0(980)\eta(1405) \to \pi^{0} f_0(980) and η(1405)π0a0(980)\eta(1405) \to \pi^{0} a_0(980) reactions with an aim to determine the isospin violation and the mixing of the f0(980)f_0(980) and a0(980)a_0(980) resonances. We make use of the chiral unitary approach where these two resonances appear as composite states of two mesons, dynamically generated by the meson-meson interaction provided by chiral Lagrangians. We obtain a very narrow shape for the f0(980)f_0(980) production in agreement with a BES experiment. As to the amount of isospin violation, or f0(980)f_0(980) and a0(980)a_0(980) mixing, assuming constant vertices for the primary η(1405)π0KKˉ\eta(1405)\rightarrow \pi^{0}K\bar{K} and η(1405)π0π0η\eta(1405)\rightarrow \pi^{0}\pi^{0}\eta production, we find results which are much smaller than found in the recent experimental BES paper, but consistent with results found in two other related BES experiments. We have tried to understand this anomaly by assuming an I=1 mixture in the η(1405)\eta(1405) wave function, but this leads to a much bigger width of the f0(980)f_0(980) mass distribution than observed experimentally. The problem is solved by using the primary production driven by ηKKˉ\eta' \to K^* \bar K followed by KKπK^* \to K \pi, which induces an extra singularity in the loop functions needed to produce the f0(980)f_0(980) and a0(980)a_0(980) resonances. Improving upon earlier work along the same lines, and using the chiral unitary approach, we can now predict absolute values for the ratio Γ(π0,π+π)/Γ(π0,π0η)\Gamma(\pi^0, \pi^+ \pi^-)/\Gamma(\pi^0, \pi^0 \eta) which are in fair agreement with experiment. We also show that the same results hold if we had the η(1475)\eta(1475) resonance or a mixture of these two states, as seems to be the case in the BES experiment

    Preliminary Studies about Synthesis and Electrical Properties of Ruthenium Doped Lanthanum Strontium Titanate as a Potential Anode of Solid Oxide Fuel Cells

    Get PDF
    The lanthanum strontium titanate (LST) is one of the most representative alternative anode materials. Although it shows low catalytic properties, the disadvantage could be improved by doping of ruthenium which is widely used as catalyst under steam reforming reaction or oxidation reaction. The ruthenium doped lanthanum strontium titanates (LSTRs) powders were synthesized by complex EDTA-citrate method showing well crystallinity. Additionally, the prepared samples were evaluated through various experimental tests. For example, the stability in the reducing atmosphere and chemical compatibility with YSZ electrolyte such as reactivity test in high temperature were confirmed by XRD (X-ray diffraction). And electrical conductivity in wet H-2 atmosphere at 900 degrees C is about 350.6 S/cm, 342.4 S/cm and 179.1 S/cm with sintered bar of LST, LSTR0.02 and LSTR0.05, respectively.open1111Nsciescopu

    Comparative study of CXC chemokines modulation in brown trout (Salmo trutta) following infection with a bacterial or viral pathogen

    Get PDF
    Acknowledgements We would like to acknowledge Richard Paley, Tom Hill and Georgina Rimmer for their collaboration during brown trout infection challenges in CEFAS-Weymouth biosecurity facilities. Bartolomeo Gorgoglione, Stephen W. Feist and Nick G. H. Taylor were supported by a DEFRA grant (F1198).Peer reviewedPostprin
    corecore