Anomalous electronic Raman scattering in NaxCoO2.yH2O.
نویسندگان
چکیده
Raman scattering experiments on NaxCoO2.yH2O single crystals show a broad electronic continuum with a pronounced peak around 100 cm(-1) and a cutoff at approximately 560 cm(-1) over a wide range of doping levels. The electronic Raman spectra in superconducting and nonsuperconducting samples are similar at room temperature, but evolve in markedly different ways with decreasing temperature. For superconducting samples, the low-energy spectral weight is depleted upon cooling below T* approximately 150 K, indicating the opening of a pseudogap that is not present in nonsuperconducting materials. Weak additional phonon modes observed below T* suggest that the pseudogap is associated with charge ordering.
منابع مشابه
Weak Magnetic Order in the Bilayered-hydrate NaxCoO2 · yH2O Structure Probed by Co Nuclear Quadrupole Resonance — Proposed Phase Diagram in Superconducting NaxCoO2 · yH2O —
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ورودعنوان ژورنال:
- Physical review letters
دوره 96 16 شماره
صفحات -
تاریخ انتشار 2006