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Phonon scattering and stability of Na_0.5CoO_2

X. N. Zhang·P. Lemmens·V. Gnezdilov·K. Y. Choi·B. Keimer·D. P. Chen·C. T. Lin·F. C. Chou
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Abstract

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 compared to samples with larger x. An in-situ annealing study (T_max=550 K) with the initial presence of water vapor at ambient conditions reveals an irreversible structural instability of this composition.

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X. N. Zhang, P. Lemmens, V. Gnezdilov, K. Y. Choi, B. Keimer, D. P. Chen, C. T. Lin, F. C. Chou. 2004-12-23. Phonon scattering and stability of Na_0.5CoO_2. https://doi.org/10.1016/j.physb.2005.01.085

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