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相关论文: Lattice and electronic anomalies of CaFe_2As_2 stu…

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We report a comprehensive temperature dependent Raman measurements on three different phases of monolayer WS2 from 4K to 330K in a wide spectral range. Our studies revels the anomalous nature of the first as well as the higher order…

材料科学 · 物理学 2020-01-08 Deepu Kumar , Birender Singh , Pawan Kumar , Viswanath Balakrishnan , Pradeep Kumar

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…

Crystals of tetracene have been studied by means of lattice phonon Raman spectroscopy as a function of temperature and pressure. Two different phases (polymorphs I and II) have been obtained, depending on sample preparation and history.…

We have performed Raman scattering investigations on the high energy magnetic excitations in a BiFeO$_3$ single crystal as a function of both temperature and laser excitation energy. A strong feature observed at 1250 cm$^{-1}$ in the Raman…

强关联电子 · 物理学 2018-11-13 M. Cazayous , A. Sacuto , D. Lebeugle , D. Colson

A Raman scattering study covering the entire substitution range of the FeSe$_{1-x}$S$_x$ solid solution is presented. Data were taken as a function of sulfur concentration $x$ for $0\le x \le 1$, of temperature and of scattering symmetry.…

BaNi$_2$As$_2$ is a nonmagnetic analogue of the iron pnictide superconductors, and in its tetragonal state exhibits an incommensurate charge-density-wave (IC-CDW) and a sizable elastoresistance. In this work, phonons in BaNi$_2$As$_2$…

We present detailed ab-initio lattice dynamical analysis of the Fe-O infinite-layer compounds CaFeO2 and SrFeO2 in various magnetic configurations. These indicate strong spin-phonon coupling in SrFeO2 in contrast to that in case of CaFeO2.…

材料科学 · 物理学 2016-09-13 M. K. Gupta , R. Mittal , S. L. Chaplot , Cedric Tassel , Hiroshi Kageyama

Using a combination of infrared ellipsometry, time-domain terahertz spectroscopy, and far-infrared reflectometry we have obtained the $ac$-plane complex dielectric function of monoclinic ($C2/c$) Ta$_2$NiSe$_5$ and orthorhombic ($Cmcm$)…

强关联电子 · 物理学 2018-09-12 T. I. Larkin , R. D. Dawson , M. Höppner , T. Takayama , M. Isobe , Y. -L. Mathis , H. Takagi , B. Keimer , A. V. Boris

The Raman spectrum of the $B_{1g}$ phonon in the superconducting cuprate materials is investigated theoretically in detail in both the normal and superconducting phases, and is contrasted with that of the $A_{1g}$ phonon. A mechanism…

凝聚态物理 · 物理学 2009-10-22 T. P. Devereaux , A. Virosztek , A. Zawadowski

We report measurements of the phonon density of states as measured with inelastic x-ray scattering in SmFeAsO$_{1-x}$F$_y$ powders. An unexpected strong renormalization of phonon branches around 23 meV is observed as fluorine is substituted…

We have performed extensive ab initio calculations to investigate phonon dynamics and their possible role in superconductivity in BaFe2As2 and related systems. The calculations are compared to inelastic neutron scattering data that offer…

超导电性 · 物理学 2009-11-13 M. Zbiri , H. Schober , M. R. Johnson , S. Rols , R. Mittal , Y. Su , M. Rotter , D. Johrendt

The analysis of phonon anomalies provides valuable information about the cooperative dynamics of lattice, spin and charge degrees of freedom. Significant is the anomalous temperature dependence of the external modes observed in…

强关联电子 · 物理学 2010-05-24 Ch. Hartinger , F. Mayr , A. Loidl , T. Kopp

Resonance Raman scattering, which probes electrons, phonons and their interplay in crystals, is extensively used in two-dimensional materials. Here we investigate Raman modes in MoSe$_2$ at different laser excitation energies from 2.33 eV…

We report an infrared reflection spectroscopy study of La$_{1/2}$Ca$_{1/2}$MnO$_3$ over a broad frequency range and temperature interval which covers the transitions from the high temperature paramagnetic to ferromagnetic and, upon further…

强关联电子 · 物理学 2009-11-10 A. P. Litvinchuk , M. N. Iliev , M. Pissas , C. W. Chu

The temperature dependence below $T_{c}$ of the lineshape of optical phonons of different symmetry as seen in Raman scattering is investigated for superconductors with anisotropic energy gaps. It is shown that the symmetry of the…

凝聚态物理 · 物理学 2009-10-22 T. P. Devereaux

The thin films of lead free magneto-electric compound AlFeO3 have been deposited using pulsed laser deposition technique. X-ray diffraction, X-ray absorption spectroscopy and reflectivity measurements established the orthorhombic structure…

材料科学 · 物理学 2019-01-15 Shekhar Tyagi , Gaurav Sharma , R. J. Choudhary , Vasant G. Sathe

The isospin-phonon coupling in Sr2IrO4 is investigated by temperature dependent phonon Raman scattering. Anomalous behavior in the frequency of all studied optical phonons is observed below the magnetic transition temperature TN ~240 K. The…

强关联电子 · 物理学 2019-04-23 Kousik Samanta , Danilo Rigitano , Pascoal Jose Giglio Pagliuso , Eduardo Granado

Here, we present the phonon calculations for thermodynamic properties, thermal expansion and lattice thermal conductivity of Fe$_{2}$VAl in the temperature range of $300-800$ K and compared with existing experiment. Phonon dispersion is…

材料科学 · 物理学 2022-07-13 Shamim Sk , Sudhir K. Pandey

In Fe-As based superconductors magnetism and superconductivity show strong sensitivity to the lattice, suggesting a possibility of unconventional electron-phonon coupling. We investigated c-axis polarized phonons in doped and undoped…

Probing phonons, quasi-particle excitations and their coupling has enriched our understanding of these 2D materials and proved to be crucial for developing their potential applications. Here, we report comprehensive temperature, 4-330 K,…

材料科学 · 物理学 2022-03-14 Deepu Kumar , Vivek Kumar , Rahul Kumar , Mahesh Kumar , Pradeep Kumar