Lattice and electronic anomalies of CaFe_2As_2 studied by Raman spectroscopy

Abstract

We report inelastic light scattering experiments on CaFe_2As_2 in the temperature range of 4 to 290 K. In in-plane polarizations two Raman-active phonon modes are observed at 189 and 211 cm-1, displaying A_1g and B_1g symmetries, respectively. Upon heating through the tetragonal-to-orthorhombic transition at about T_S=173 K, the B_1g phonon undergoes a discontinuous drop of the frequency by 4 cm-1 whereas the A_1g phonon shows a suppression of the integrated intensity. Their linewidth increases strongly with increasing temperature and saturates above T_S. This suggests (i) a first-order structural phase transition and (ii) a drastic change of charge distribution within the FeAs plane through T_S.

4 pages, 4 figures

References in corpus (12)

• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• Superconductivity at 43 K in Samarium-arsenide Oxides $SmFeAs{O}_{1-x}{F}_x$
• Spin density wave anomaly at 140 K in the ternary iron arsenide BaFe2As2
• Inelastic Light Scattering From Correlated Electrons
• Is LaO${}_{1-x}$F${}_x$FeAs an electron-phonon superconductor ?
• Origin of the ~150 K Anomaly in LaOFeAs; Competing Antiferromagnetic Superexchange Interactions, Frustration, and Structural Phase Transition
• Anisotropic thermodynamic and transport properties of single crystalline (Ba${}_{1-x}$K${}_x$)Fe${}_2$As${}_2$ (x = 0 and 0.45)
• Lattice and magnetic instabilities in CaFe2As2: A single crystal neutron diffraction study
• First order structural phase transition in CaFe${}_2$As${}_2$
• Structural transition and anisotropic properties of single crystalline SrFe2As2
• Anisotropic three-dimensional magnetism in CaFe2As2
• Raman scattering study of (K${}_x$Sr${}_{1-x}$)Fe${}_2$As${}_2$ ($x$ = 0.0, 0.4)

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