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Related papers: Soft and Isotropic Phonons in PrFeAsO_{1-y}

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We report an inelastic x-ray scattering investigation of phonons in FeSe superconductor. Comparing the experimental phonon dispersion with density functional theory (DFT) calculations in the non-magnetic state, we found a significant…

The electronic structures, lattice dynamics, and magnetic properties of crystal {\beta}-FeSe under hydrostatic pressure have been studied by using the first-principles electronic structure calculations with van der Waals (vdW) corrections.…

Superconductivity · Physics 2013-11-25 Qian-Qian Ye , Kai Liu , Zhong-Yi Lu

We have carried out an extensive phonon study on multiferroic GaFeO3 to elucidate its dynamical behavior. Inelastic neutron scattering measurements are performed over a wide temperature range, 150 to 1198 K. First principles lattice…

Materials Science · Physics 2015-06-19 M. K. Gupta , R. Mittal , M. Zbiri , Ripandeep Singh , S. Rols , H. Schober , S. L. Chaplot

A first-principles-based method for computing phonons of magnetic random solid solutions including thermal magnetic fluctuations is developed. The method takes fluctuations of force constants (FCs) due to magnetic excitations as well as due…

Materials Science · Physics 2019-08-07 Yuji Ikeda , Fritz Körmann , Biswanath Dutta , Abel Carreras , Atsuto Seko , Jörg Neugebauer , Isao Tanaka

Resistivity, magnetic susceptibility, neutron scattering and x-ray crystallography measurements were used to study the evolution of magnetic order and crystallographic structure in single-crystal samples of the Ba1-xSrxFe2As2 and…

Superconductivity · Physics 2012-09-06 K. Kirshenbaum , N. P. Butch , S. R. Saha , P. Y. Zavalij , B. G. Ueland , J. W. Lynn , J. Paglione

We determine the nature of coupled phonons and magnetic excitations in AlFeO3 using inelastic light scattering from 5 K to 315 K covering a spectral range from 100-2200 cm-1 and complementary first-principles density functional theory-based…

Strongly Correlated Electrons · Physics 2012-05-01 Pradeep Kumar , A. Bera , D. V. S. Muthu , S. N. Shirodkar , R. Saha , A. Shireen , A. Sundaresan , U. V. Waghmare , A. K. Sood , C. N. R. Rao

To shed light on the role of magnetism on the superconducting mechanism of the oxygen-free FeAs pnictides, we investigate the effect of magnetic ordering on phonon dynamics in the low-temperature orthorhombic parent compounds, which present…

We have carried out temperature-dependent x-ray diffraction and Raman scattering experiments on powder $Cs_3Bi_2Br_9$. Trigonal to monoclinic structural transition at around 95 K is discussed and shown to be driven by the softening of the…

We report a Raman study of the effect of temperature on the self-energies of optical phonons in a number of transition metals with hexagonal-close-packed structure. Anisotropic softening of phonon energies and narrowing of phonon linewidths…

Materials Science · Physics 2017-01-04 Yu. S. Ponosov , S. V. Streltsov

The effect of the electron-phonon interaction on magnetization relaxation is studied within the framework of first-principles scattering theory for Fe, Co, and Ni by displacing atoms in the scattering region randomly with a thermal…

Materials Science · Physics 2011-09-06 Yi Liu , Anton A. Starikov , Zhe Yuan , Paul J. Kelly

The Fe(1+x)Sb compound has been synthesized close to stoichiometry with x = 0.023(8). The compound was investigated by 57Fe M\"ossbauer spectroscopy in the temperature range 4.2 - 300 K. The antiferromagnetic ordering temperature was found…

Strongly Correlated Electrons · Physics 2016-01-20 K. Komedera , A. K. Jasek , A. Blachowski , K. Ruebenbauer , A. Krzton-Maziopa

We report temperature-dependent Raman scattering and X-ray diffraction studies of pyrochlore iridates, (Eu$_{1-x}$Bi$_x$)$_2$Ir$_2$O$_7$, for x=0, 0.02, 0.035, 0.05 and 0.1. The temperature variation in Raman experiments spans from 4 K to…

Strongly Correlated Electrons · Physics 2022-03-14 Anoop Thomas , Prachi Telang , Kshiti Mishra , Martin Cesnek , Jozef Bednarcik , D V S Muthu , Surjeet Singh , A K Sood

We present an inelastic light scattering study of single crystalline (La$_{1-y}$Pr$_y$)$_{1-x}$Sr$_{x}$MnO$_3$ ($0\leq x\leq0.14$,$y=0$ and $x=1/8$,$0\leq y\leq0.5$). A giant softening up to 20 - 30 cm$^{-1}$ of the Mn-O breathing mode has…

We have carried out temperature and pressure-dependent Raman and x-ray measurements on single crystals of Tb$_2$Ti$_2$O$_7$. We attribute the observed anomalous temperature dependence of phonons to phonon-phonon anharmonic interactions. The…

We report the crystal growth and structural, magnetic, conductivity, and specific heat investigations of Rb(1-x)Fe(2-y)Se2 single crystals with varying stoichiometry prepared by self-flux and Bridgman methods. The system exhibits a strongly…

Superconductivity · Physics 2011-11-01 V. Tsurkan , J. Deisenhofer , A. Günther , H. -A. Krug von Nidda , S. Widmann , A. Loidl

Iron mono-arsenide in the powder form has been investigated by transmission 57Fe Moessbauer spectroscopy in the temperature range 4.2 - 1000 K. Additional spectra have been obtained at 20 K and 100 K applying external magnetic field of 7 T.…

Materials Science · Physics 2013-09-02 A. Blachowski , K. Ruebenbauer , J. Zukrowski , Z. Bukowski

We report on the phonon spectrum probed at the $\beta$--FeSe(001) surface by means of high-resolution electron energy-loss spectroscopy (HREELS). Single crystals of $\beta$--FeSe are cleaved under ultra-high vacuum conditions and are…

Superconductivity · Physics 2017-11-21 Khalil Zakeri , Tobias Engelhardt , Thomas Wolf , Matthieu Le Tacon

Temperature dependence of longitudinal optical phonons with oxygen character was measured in La1-xSrxMnO3 (x=0.2, 0.3) by inelastic neutron scattering in the (1 0 0) cubic direction. The zone center mode intensity is consistent with the…

Strongly Correlated Electrons · Physics 2007-05-23 D. Reznik , W. Reichardt

We report temperature evolution of coherently excited acoustic and optical phonon dynamics in superconducting iron pnictide single crystal Ca(Fe_0.944Co_0.056)_2As_2 across the spin density wave transition at T_SDW ~ 85 K and…

Strongly Correlated Electrons · Physics 2012-12-14 Sunil Kumar , L. Harnagea , S. Wurmehl , B. Buchner , A. K. Sood

Polarized Raman-scattering spectra of superconducting, single-crystalline FeSe evidence pronounced phonon anomalies with temperature reduction. A large 6.5% hardening of the B_1g(Fe) phonon mode is attributed to the suppression of local…