Related papers: Anomalous phonon behavior in the high temperature …
A crack free and high structural quality Sr2Nb2O7 single crystals were grown by the optical float zone method using optimized growth parameters. Laue pattern confirms single crystalline nature of the grown crystal. Temperature dependent…
Many complex crystals show a flattening or even increasing lattice thermal conductivity at high temperatures, which deviates from the traditional 1/T decay trend given by conventional phonon theory. In this work, we predict the thermal…
Inelastic neutron scattering is used to measure the temperature dependent phonon dispersion in Ca$_{2-x}$Sr$_{x}$RuO$_{4}$ ($x=0.4$, 0.6). The in-plane $\Sigma_{4}$ octahedral tilt mode softens significantly at the zone boundary of the high…
We report incommensurate diffuse (ICD) scattering appearing in the high-temperature-tetragonal (HTT) phase of La$_{2-x}$(Sr,Ba)$_{x}$CuO$_{4}$ with $0.07 \leq x \leq 0.20$ observed by the neutron diffraction technique. For all compositions,…
The corrosion property of Nickel-titanium (NiTi) shape memory alloy is investigated during forward martensitic transformation between 40C and 0C. The Differential Scanning Calorimetry technique is used to find the forward and reverse…
Shape memory effect associated with martensitic transformations is of the rapidly developing field in nanotechnologies, where industrial use of systems established on that effect provide greater flexibility on the nano-devices fabrication…
In this work, we performed temperature-dependent Raman spectroscopy studies on three layered metal thiophosphates: CuInP2S6, CuCrP2S6, and CuInP2S6-In4/3P2S6 heterostructures. These materials are emerging multiferroics, with CuInP2S6 and…
We have used neutron scattering techniques to characterize the diffuse scattering and lattice dynamics in single crystals of the relaxor PMN from 10K to 900K. We observed two distinct types of diffuse scattering. The first is weak,…
The temperature and magnetic field dependence of lattice and carrier excitations in MnSi is studied in detail using inelastic light scattering. The pure symmetry components of the electronic response are derived from the polarization…
Thermal expansion of {\alpha}-rhombohedral boron ({\alpha}-B12) and two isostructural boron-rich pnictides (B12P2 and B12As2) has been studied between 298 and 1280 K by high-temperature synchrotron X-ray diffraction. For all studied phases…
The intrinsic linewidth $\Gamma_{TA}$ of the transverse acoustic (TA) phonon observed in the relaxor ferroelectric compound Pb(Mg$_{1/3}$Nb$_{2/3})_{0.8}$Ti$_{0.2}$O$_3$ (PMN-20%PT) begins to broaden with decreasing temperature around 650…
Magnetic phase diagrams of the metamagnetic shape memory alloys Ni50-xCoxMn31.5Ga18.5 (x = 9 and 9.7) were produced from high-field magnetization measurements up to 56 T. For both compounds, magnetic field induced martensitic…
PbTe crystals have a soft transverse optical phonon mode in the terahertz frequency range, which is known to efficiently decay into heat-carrying acoustic phonons, resulting in anomalously low thermal conductivity. Here, we studied this…
The strongly correlated material FeSi exhibits several unusual thermal, magnetic, and structural properties under varying pressure-temperature (P-T) conditions. It is a potential thermoelectric alloy and a materials of several geological…
We report an anomalous temperature-induced transition in thermal conductivity in germanene monolayer around a critical temperature $T_c = 350 \, \text{K}$. Equilibrium molecular dynamics simulations reveal a transition from $\kappa \sim…
Dirac semimetal PdTe2 single-crystal temperature-dependent ultrafast carrier and phonon dynamics were studied using ultrafast optical pump-probe spectroscopy. Two distinct carrier and coherent phonons relaxation processes were identified in…
Inelastic x-ray scattering is used to investigate charge density wave (CDW) formation and the low-energy lattice dynamics of the underdoped high temperature superconductor ortho-II YBa2Cu3O6.54. We find that, for a temperature ~1/3 of the…
We employ polarization-resolved Raman spectroscopy to study the lattice dynamics of the polar charge density wave phase of the superconductor Mo$_3$Al$_2$C with structural chirality. We show the phononic signatures of the charge density…
Degenerate pump-probe reflectivity experiments have been performed on a single crystal of bismuth telluride (Bi$_2$Te$_3$) as a function of sample temperature (3K to 296K) and pump intensity using $\sim$ 50 femtosecond laser pulses with…
Phonons, quantized vibrations of the atomic lattice, are fundamental to understanding thermal transport, structural stability, and phase behavior in crystalline solids. Despite advances in computational materials science, most predictions…