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Updated: Jun 3, 2026

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Temperature-dependent Raman study of a CeFeAsO(0.9)F(0.1) superconductor: crystal field excitations, phonons and
Pradeep Kumar1, Anil Kumar, Surajit Saha
1Department of Physics, Indian Institute of Science, Bangalore, India.
Abstract:
We report temperature-dependent Raman spectra of CeFeAsO(0.9)F(0.1) from 4 to 300 K in the spectral range of 60-1800 cm(-1) and interpret them using estimates of phonon frequencies obtained from first-principles density functional calculations. We find evidence for strong coupling between the phonons and crystal field excitations; in particular the Ce(3 + ) crystal field excitation at 432 cm(-1) couples strongly with the E(g) 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 T(c), thus estimated to be ~10, suggests CeFeAsO(0.9)F(0.1) to be a strong coupling superconductor. In addition, two high frequency modes observed at 1342 and 1600 cm(-1) are attributed to electronic Raman scattering from the (x(2)-y(2)) to xz /yz d-orbitals of Fe.
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