Phonon anomalies in pure and underdoped R{1-x}K{x}Fe{2}As{2} R = Ba, Sr investigated by Raman light scattering - Condensed Matter > SuperconductivityReportar como inadecuado




Phonon anomalies in pure and underdoped R{1-x}K{x}Fe{2}As{2} R = Ba, Sr investigated by Raman light scattering - Condensed Matter > Superconductivity - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: We present a detailed temperature dependent Raman light scattering study ofoptical phonons in Ba{1-x}K{x}Fe{2}As{2} x ~ 0.28, superconducting Tc ~ 29 K,Sr{1-x}K{x}Fe{2}As{2} x ~ 0.15, Tc ~ 29 K and non-superconductingBaFe{2}As{2} single crystals. In all samples we observe a strong continuousnarrowing of the Raman-active Fe and As vibrations upon cooling below thespin-density-wave transition Ts. We attribute this effect to the opening of thespin-density-wave gap. The electron-phonon linewidths inferred from these datagreatly exceed the predictions of ab-initio density functional calculationswithout spin polarization, which may imply that local magnetic moments survivewell above Ts. A first-order structural transition accompanying thespin-density-wave transition induces discontinuous jumps in the phononfrequencies. These anomalies are increasingly suppressed for higher potassiumconcentrations. We also observe subtle phonon anomalies at the superconductingtransition temperature Tc, with a behavior qualitatively similar to that in thecuprate superconductors.



Autor: M. Rahlenbeck, G. L. Sun, D. L. Sun, C. T. Lin, B. Keimer, C. Ulrich

Fuente: https://arxiv.org/







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