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.

arXiv comment4 pages, 4 figures

References in corpus (13)

• 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)
• Anomalous electronic Raman scattering in Na_xCoO_2 H_2O

Cited by in corpus (42)

• Effects of the magnetic orderings on the dynamical conductivity: optical investigations of EuFe${}_2$As${}_2$ single crystals
• Doping dependence of the lattice dynamics in Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$ studied by Raman spectroscopy
• Phonon anomaly in BaFe2As2
• Magnetic interactions in iron superconductors: A review
• Phonon anomalies in pure and underdoped R{1-x}K{x}Fe{2}As{2} (R = Ba, Sr) investigated by Raman light scattering
• Anomalous Raman scattering from phonons and electrons of superconducting FeSe${}_{0.82}$
• Coherent excitations and electron phonon coupling in Ba/EuFe_2As_2 compounds investigated by femtosecond time- and angle-resolved photoemission spectroscopy
• Ultrafast Quasiparticle Dynamics and Electron-Phonon Coupling in (Li0.84Fe0.16)OHFe0.98Se
• Raman scattering study of Spin-Density-Wave order and electron-phonon coupling in Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$
• Anomalous optical phonons in FeTe pnictides: spin state, magnetic order, and lattice anharmonicity
• Optical and Raman spectroscopy studies on Fe-based superconductors
• Anomalous dependence of the c-axis polarized Fe B${}_{1g}$ phonon mode with Fe and Se concentrations in Fe${}_{1+y}$Te${}_{1-x}$Se${}_x$
• Electron-phonon coupling in cuprate and iron-based superconductors revealed by Raman scattering
• Charge Density Wave order and electron-phonon coupling in ternary superconductor Bi${}_2$Rh${}_3$Se${}_2$
• Ultrafast Optical Spectroscopy Evidence of Pseudogap and Electron-Phonon Coupling in an Iron-Based Superconductor KCa${}_2$Fe${}_4$As${}_4$F${}_2$
• Frustrated spin order and stripe fluctuations in FeSe
• Self-energy effects and electron-phonon coupling in Fe-As superconductors
• Interplay of lattice, electronic and spin degrees of freedom in detwinned BaFe${}_2$As${}_2$: a Raman scattering study
• Spin-Density-Wave Gap with Dirac Nodes and Two-Magnon Raman Scattering in BaFe2As2
• Temperature and Pressure Dependence of the Fe-specific Phonon Density of States in Ba(Fe(1-x)Co(x))2As2
• Effects of magnetic doping and temperature dependence on phonon dynamics in CaFe\_{1-x}Co\_{x}AsF compounds (x = 0, 0.06, 0.12)
• Raman Scattering Study of the Lattice Dynamics of Superconducting LiFeAs
• Optical properties of the iron-pnictide analog BaMn2As2
• Soft and Isotropic Phonons in PrFeAsO_{1-y}
• Raman scattering study of electron-doped Pr${}_x$Ca${}_{1-x}$Fe${}_2$As${}_2$ superconductors
• Anharmonic softening of Raman active phonons in Iron-Pnictides; estimating the Fe isotope effect due to anharmonic expansion
• Phonon Anomalies, Orbital-Ordering and Electronic Raman Scattering in iron-pnictide Ca(Fe0.97Co0.03)2As2: Temperature-dependent Raman Study
• Temperature-dependent Raman study of CeFeAsO0.9F0.1 Superconductor: Crystal field excitations, phonons and their coupling
• Coupling of the A_{1g} As-phonon to magnetism in iron pnictides
• Nematic Fluctuations and Phase Transitions in LaFeAsO: a Raman Scattering Study
• Raman Evidence for Superconducting Gap and Spin-Phonon Coupling in Superconductor Ca(Fe0.95Co0.05)2As2
• Anomalous magneto-elastic coupling in Au-doped BaFe2As2
• Raman scattering in iron-based superconductors
• Experimental investigation of electronic interactions in collapsed and uncollapsed LaFe2As2 phases
• Superconductivity-induced Phonon Renormalization on NaFe${}_{1-x}$Co${}_x$As
• Raman scattering investigation of superconducting Ba${}_2$Ti${}_2$Fe${}_2$As${}_4$O
• The Hidden Nematic Fluctuations in the Triclinic (Ca0.85La0.15)10(Pt3As8)(Fe2As2)5 Superconductor Revealed by Ultrafast Optical Spectroscopy
• Magneto-elastic coupling in Fe-based superconductors
• Vibrational anomalies in AFe${}_2$As${}_2$ (A$=$Ca, Sr, and Ba) single crystals
• Small influence of magnetic ordering on lattice dynamics in TaFe${}_{1.25}$Te${}_3$
• Interplay of electron-phonon coupling, pseudogap, and superconductivity in CsCa${}_2$Fe${}_4$As${}_4$F${}_2$ studied using ultrafast optical spectroscopy
• Transient gap generation in BaFe${}_2$As${}_2$ driven by coherent lattice vibrations