Related papers: Two-phonon coupling to the antiferromagnetic phase…
Temperature dependent X-ray diffraction and Raman spectroscopic studies were carried out on the flux grown single crystals of gallium ferrite with Ga:Fe ratio of 0.9:1.1. Site occupancy calculations from the Rietveld refinement of the X-ray…
Type-II multiferroics, where spin interactions induce a ferroelectric polarization, are interesting for new device functionalities due to large magnetoelectric coupling. We report on a new type of multiferroicity in the quadruple-perovskite…
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…
Micro-Raman spectroscopy has been used to study lattice dynamics associated with the ferroelectric domains of a BiFeO$_3$ single crystal at low temperature. The phonon assignment shows a large frequency splitting between the transverse and…
We report experimental evidence for pressure instabilities in the model multiferroic BiFeO3 and namely reveal two structural phase transitions around 3 GPa and 10 GPa by using diffraction and far-infrared spectroscopy at a synchrotron…
We report plane-polarized Raman scattering spectra of iron oxypnictide superconductor NdFeAsO$_{1-x}$F$_x$ single crystals with varying fluorine $x$ content. The spectra exhibit sharp and symmetrical phonon lines with a weak dependence on…
We explore the Fano resonance in ZrTe5, using Raman scattering measurements. We identified two closely spaced B2g phonon modes, B2g I and B2g II, around 9 meV and 10 meV, respectively. Interestingly, only B2g I exhibited the Fano resonance,…
We have studied spectral evolution of the $E_u^1$ phonon line of a topological insulator Bi$_{2-x}$Sr$_x$Se$_3$ with temperature. Unlike the Raman-active phonons, the $E_u^1$ mode demonstrates softening upon cooling the crystal, and the…
We present a magneto-infrared spectroscopic study of thin Bi2Se3 single crystal flakes. Magneto-infrared transmittance and reflectance measurements are performed in the Faraday geometry at 4.2K in a magnetic field up to 17.5T. Thin Bi2Se3…
We performed factor-group analysis of all phonons in possible monoclinic C2/c and C2 structures of BiMnO3 and compared it with our experimental infrared and Raman spectra. We conclude that the crystal structure is centrosymmetric C2/c in…
BiFeO3 (BFO) multiferroic oxide has a complex phase diagram that can be mapped by appropriately substrate-induced strain in epitaxial films. By using Raman spectroscopy, we conclusively show that films of the so-called supertetragonal T-BFO…
The application of weak electric fields (<~ 100 V/cm) is found to dramatically enhance the lattice thermal conductivity of the antiferromagnetic (AF) insulator CaMnO(3) over a broad range of temperature about the Neel ordering point (125…
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…
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,…
We present experimental evidence of an intriguing phase transition between distinct topological states in the type-II Weyl semimetal MoTe2. We observe anomalies in the Raman phonon frequencies and linewidths as well as electronic…
In this work we study phonon-phonon coupling in bismuth vanadate (BiVO4), known for its second-order transition involving a variety of coupling mechanisms. Using Raman spectroscopy as a probe, we identify two optical coupled phonon modes of…
Spin-phonon coupling effects, as reflected in phonon frequency shifts between ferromagnetic (FM) and G-type antiferromagnetic (AFM) configurations in cubic CaMnO$_3$, SrMnO$_3$, BaMnO$_3$, LaCrO$_3$, LaFeO$_3$ and La$_2$(CrFe)O$_6$, are…
Two-dimensional (2D) magnetic materials have attracted much recent interest with unique properties emerging at the few-layer limit. Beyond the reported impacts on the static magnetic properties, the effects of reducing the dimensionality on…
We present a comprehensive temperature and polarization dependent inelastic light scattering (Raman) study on single crystals of two-dimensional CuCrP2S6, a layered van der Waals material exhibiting coupled magnetic and electric degrees of…
We report inelastic light scattering studies on Ca(Fe0.97Co0.03)2As2 in a wide spectral range of 120-5200 cm-1 from 5K to 300K, covering the tetragonal to orthorhombic structural transition as well as magnetic transition at Tsm ~ 160K. The…