Temperature-dependent Raman study of CeFeAsO0.9F0.1 Superconductor: Crystal field excitations, phonons and their coupling

Abstract

We report temperature-dependent Raman spectra of CeFeAsO0.9F0.1 from 4 K to 300 K in spectral range of 60 to 1800 cm-1 and interpret them using estimates of phonon frequencies obtained from first-principles density functional calculations. We find evidence for a strong coupling between the phonons and crystal field excitations; in particular Ce3+ crystal field excitation at 432 cm-1 couples strongly with Eg oxygen vibration at 389 cm-1 . Below the superconducting transition temperature, the phonon mode near 280 cm-1 shows softening, signaling its coupling with the superconducting gap. The ratio of the superconducting gap to Tc thus estimated to be ~ 10 suggests CeFeAsO0.9F0.1 as a strong coupling superconductor. In addition, two high frequency modes observed at 1342 cm-1 and 1600 cm-1

References in corpus (24)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• Superconductivity at 43 K in Samarium-arsenide Oxides $SmFeAs{O}_{1-x}{F}_x$
• Superconductivity at 41 K and its competition with spin-density-wave instability in layered CeO${}_{1-x}$F${}_x$FeAs
• Superconductivity and Phase Diagram in the Iron-based Arsenic-oxides ReFeAsO1-delta (Re = rare earth metal) without F-Doping
• Strong Correlations and Magnetic Frustration in the High Tc Iron Pnictides
• Is LaO${}_{1-x}$F${}_x$FeAs an electron-phonon superconductor ?
• Superconductivity at 25 K in hole doped $(L{a}_{1-x}S{r}_x)OFeAs$
• Coherence-incoherence crossover in the normal state of iron-oxypnictides and importance of the Hund's rule coupling
• The challenge of unravelling magnetic properties in LaFeAsO
• Electron-Hole Symmetry and Magnetic Coupling in Antiferromagnetic LaOFeAs
• Momentum-dependence of Superconducting Gap, strong-coupling dispersion Kink, and tightly bound Cooper pairs in the high-Tc (Sr,Ba)1-x(K,Na)xFe2As2 superconductors
• Theory of the Magnetic Moment in Iron Pnictides
• Raman scattering study of (K${}_x$Sr${}_{1-x}$)Fe${}_2$As${}_2$ ($x$ = 0.0, 0.4)
• Phonon anomalies in pure and underdoped R{1-x}K{x}Fe{2}As{2} (R = Ba, Sr) investigated by Raman light scattering
• Phonon Density of States of LaFeAsO1-xFx
• Lattice and electronic anomalies of CaFe_2As_2 studied by Raman spectroscopy
• Anomalous Raman scattering from phonons and electrons of superconducting FeSe${}_{0.82}$
• The crystalline electric field as a probe for long range antiferromagnetic order and superconductivity in CeFeAsO${}_{1-x}$F${}_x$
• Superconducting energy gap and c-axis plasma frequency of (Nd,Sm)O0.82F0.18FeAs superconductors from infrared ellipsometry
• The optical phonon spectrum of SmFeAsO
• Raman spectra in iron-based quaternary CeO${}_{1-x}$F${}_x$FeAs and LaO${}_{1-x}$F${}_x$FeAs
• Temperature dependence and resonance effects in Raman scattering of phonons in NdFeAsO${}_x$F${}_{1-x}$ single crystals
• Superconductivity in CeO_{1-x}F_xFeAs with upper critical field of 94 T

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