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- Kall, M., et al.
(författare)
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Resonance Raman scattering as a probe of oxygen dynamics in YBa2Cu3Ox
- 1998
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Ingår i: Journal of Physics and Chemistry of Solids. - 0022-3697 .- 1879-2553. ; 59, s. 1988-1990
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Tidskriftsartikel (refereegranskat)abstract
- We report on the metastable photo-bleaching of the 2.15 eV yellow Raman resonance in oxygen deficient YBa2Cu3Ox (x = 6.35-6.87), extending investigations by Wake ct al. (Phys. Rev. Lett., 1991,67, 3728) for x approximate to 7. Polarization, x dependence and phonon spectra indicate that the resonance is localized at oxygen vacancies in long CuO-chains. The resonance is thermally reactivated from the metastable bleached state with a relaxation time tau similar to exp[Delta/k(B)T] with Delta approximate to 1 eV. The resulting temperature dependent equilibrium resonance intensity essentially miners the oxygen superstructure disordering around T* approximate to 100 degrees C observed in the same crystals by hard X-ray diffraction, thus offering a new effective probe of chain-oxygen dynamics in YBa2Cu3Ox. (C) 1998 Elsevier Science Ltd. All rights reserved.
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