Temperature-dependent polarized Raman spectra of electron-doped superconducting PrxCa1-xFe2As2 (0.12) single crystals are reported. All four even-parity phonons allowed by symmetry are identified. The phonon mode of B1g symmetry at 222 cm-1, which is associated with the c-axis motion of Fe ions, is found to exhibit an anomalous frequency hardening at low temperatures, that signals nonvanishing electron-phonon coupling in the superconducting state and implies that the superconducting gap magnitude 2Δc<27 meV.
|期刊||Physical Review B - Condensed Matter and Materials Physics|
|出版狀態||Published - 2011 9月 14|
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