Related papers: Lattice dynamical study of optical modes in Tl2Mn2…
We measured polarized far-infrared reflectivity and Raman scattering spectra of SrCuO$_2$ single crystals. The frequencies for infrared-active modes were determined using an oscillator-fitting procedure of reflectivity data. The Raman…
Using muon-spin-relaxation measurements we show that the pyrochlore compound Gd2Ti2O7, in its magnetically orderered phase below ~ 1 K, displays persistent spin dynamics down to temperatures as low as 20 mK. The characteristics of the…
Many functionally relevant ferroic phenomena in quantum materials can be manipulated by driving the lattice coherently with optical and terahertz pulses. New physical phenomena and non-equilibrium phases that have no equilibrium counterpart…
We report the low temperature magnetic properties of Nd$^{3+}$ pyrochlore $\rm Nd_2ScNbO_7$. Susceptibility and magnetization show an easy-axis moment, and heat capacity reveals a phase transition to long range order at $T_N=371(2)$ mK with…
First-principles density functional theory based calculations have been performed to investigate the strain-induced modifications in the electronic and vibrational properties of monolayer (ML) ZnO. Wide range of in-plane tensile and…
Strain is prominent in fabricated samples of two-dimensional semiconductors and it also serves as an exploitable tool for engineering their properties. However, quantifying strain and characterizing its spatially inhomogeneous distribution…
Combined synchrotron angle-dispersive powder diffraction and micro-Raman spectroscopy are used to investigate the pressure-induced lattice instabilities that are accompanied by T$_{\rm c}$ anomalies in YBa$_{\rm 2}$Cu$_{\rm 4}$O$_{\rm 8}$,…
Er2Ti2O7 is believed to be a realization of an XY antiferromagnet on a frustrated lattice of corner-sharing regular tetrahedra. It is presented as an example of the order-by-disorder mechanism in which fluctuations lift the degeneracy of…
The lattice dynamics of Ba$_2$CuGe$_2$O$_7$, a compound which develops Dzyaloshinsky-Moriya (DM) helical magnetism below $T_N$ = 3.2 K, has been studied by measuring the infrared reflectivity of a single crystal with the radiation polarized…
We study the finite-temperature transition in a model XY antiferromagnet on a pyrochlore lattice, which describes the pyrochlore material Er2Ti2O7. The ordered magnetic structure selected by thermal fluctuations is six-fold degenerate.…
The detailed behavior of the in-plane infrared-active vibrational modes has been determined in AFe$_2$As$_2$ (A$\,=\,$Ca, Sr, and Ba) above and below the structural and magnetic transition at $T_N=$172, 195 and 138 K, respectively. Above…
We have investigated the time dependence of remanent magnetostriction in a (La,Pr)$_{1.2}$Sr$_{1.8}$Mn$_{2}$O$_{7}$ single crystal, in order to examine the slow dynamics of lattice distortion in bilayered manganites. A competition between…
Detailed Raman spectroscopy studies on polycrystalline Sr1-xPrxTiO3 (x=0.01, 0.025, 0.05, 0.075, 0.09, 0.13, 0.15, 0.17) samples are reported elucidating the microscopic mechanism of relaxor ferroelectrics. The polar mode was observed upto…
Temperature-dependent (5 K to 300 K) Raman scattering study of A$_{1g}$/A'$_1$ phonon modes in mono-layer (1L), bilayer (2L), trilayer (3L), and tetralayer (4L) MoTe$_2$ is reported. The temperature evolution of the modes' intensity…
Strain effects on epitaxial thin films of LaNiO3 grown on different single crystalline substrates are studied by Raman scattering and first-principles simulation. New Raman modes, not present in bulk or fully-relaxed films, appear under…
High resolution X-ray scattering measurements on single crystal Tb2Ti2O7 reveal finite structural correlations at low temperatures. This geometrically frustrated pyrochlore is known to exhibit a spin liquid, or cooperative paramagnetic…
The effect of high pressures to 40 GPa on the crystal structure and lattice dynamics of AlB2 was studied by synchrotron x-ray powder diffraction, Raman spectroscopy, and first-principles calculations. There are no indications for a…
The THz spectrum of density fluctuations, $S(Q, \omega)$, of vitreous GeO$_2$ at ambient temperature was measured by inelastic x-ray scattering from ambient pressure up to pressures well beyond that of the known $\alpha$-quartz to rutile…
The polarized Raman spectra of orthorhombic RMnO3 series (R=La,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Y) were studied at room temperature. The variation of phonon frequencies with R ionic radius rR as a whole confirms the commonly accepted Raman line…
Inelastic neutron scattering data from a twinned single-crystal of YBa2Cu3O6.95 are presented that show a distinct a-b plane anisotropy in the oxygen vibrations. The Cu-O bond-stretching type phonons are simultaneously observed along the a…