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Related papers: Structure Optimization and Frozen Phonons in LiNbO…

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Recent theory has predicted large temperature differences between the in-plane (LA and TA) and out-of-plane (ZA) acoustic phonon baths in locally-heated suspended graphene. To verify these predictions, and their implications for…

Mesoscale and Nanoscale Physics · Physics 2020-03-18 Robin J. Dolleman , Gerard J. Verbiest , Yaroslav M. Blanter , Herre S. J. van der Zant , Peter G. Steeneken

We have investigated the phonon, elastic and thermodynamic properties of L1$_{2}$ phase Al$_{3}$Ta by density functional theory approach combining with quasi-harmonic approximation model. The results of phonon band structure shows that…

Materials Science · Physics 2018-04-02 W. Leini , T. Zhang , Z. Wu , N. Wei

Nonlinear phononics play important role in strong laser-solid interactions. We discuss nonlinear dynamical protocols which allow for efficient excitation and control of nonlinear phonons. We consider recent inspiring proposals: inducing…

Other Condensed Matter · Physics 2018-05-16 A. P. Itin , M. I. Katsnelson

The interplay of electronic and structural degrees of freedom is a prominent feature of many quantum materials and of particular interest in systems with strong ferroelectric fluctuations, such as SrTiO$_3$ (STO) and KTaO$_3$ (KTO). Both…

The octahedral tilting and ferroelectric-like structural transition of LiOsO3 metallic perovskite [Nature Materials 12, 1024 (2013)] was examined using first-principles density-functional theory. In LiOsO3, a-a-a- octahedral titling mode is…

Materials Science · Physics 2015-06-17 Hyunsu Sim , Bog G. Kim

We have studied the structural phase transition of multiferroic YMnO$_3$ from first principles. Using group-theoretical analysis and first-principles density functional calculations of the total energy and phonons, we perform a systematic…

Materials Science · Physics 2009-11-11 Craig J. Fennie , Karin M. Rabe

We use the synergy of infrared, terahertz, and Raman spectroscopies with DFT calculations to shed light on the magnetic and lattice properties of VI3. The structural transition at TS1 = 79 K is accompanied by a large splitting of polar…

Iron manganese trioxide (Fe0.25Mn0.75)2O3 nanocrystals were synthesized by the sol-gel method. The 80 K Mossbauer spectrum was well-fitted using two doublets representing the 8b and 24d crystallographic sites of the (FexMn1-x)2O3 phase and…

A theoretically supported experimental study of the (1-x)LaFeO3.xLaMnO3 (LFO-LMO) solid solution is being reported for the first time which reveals a phase transformation from the Pbnm and R3-c phase at a chemical composition of x=0.625.…

Materials Science · Physics 2020-12-29 E. G. Rini , Mayanak. K. Gupta , R. Mittal , A. Mekki , Mohammed H. Al Saeed , Somaditya Sen

Accurately predicting carrier mobility in strongly anharmonic solids necessitates a precise characterization of lattice dyndamics as a function of temperature. We achieve consistency with experimental electron mobility data for bulk…

Materials Science · Physics 2024-07-29 Luigi Ranalli , Carla Verdi , Marios Zacharias , Jacky Evens , Feliciano Giustino , Cesare Franchini

Lattice vibrations are highly sensitive to crystal symmetries and their changes across phase transitions. The latter can modify irreducible (co)representations and corresponding infrared and Raman selection rules of phonons. This concept is…

Barium zirconate (BaZrO$_3$) is one of the very few perovskites that is claimed to retain an average cubic structure down to \SI{0}{\K}, while being energetically very close to an antiferrodistortive phase obtained by condensation of a soft…

Alloyed MnxZn1_xPS3 samples have been grown covering the whole compositional range and studied by means of Raman spectroscopy at temperatures covering from 4K up to 850K. Our results, supported by SQUID magnetic measurements, allowed, from…

Recently colossal positive volume thermal expansion has been found in the framework compounds Ag3Co(CN)6 and Ag3Fe(CN)6. Phonon spectra have been measured using the inelastic neutron scattering technique as a function of temperature and…

Materials Science · Physics 2015-06-05 R Mittal , M. Zbiri , H. Schober , S. N. Achary , A. K. Tyagi , S. L. Chaplot

The effect of in-plane strain on the nonlinear dielectric properties of SrTiO3 epitaxial thin films is calculated using density-functional theory within the local-density approximation. Motivated by recent experiments, the structure,…

Materials Science · Physics 2009-11-10 Armin Antons , J. B. Neaton , Karin M. Rabe , David Vanderbilt

We measured the temperature dependent infrared reflectivity spectra of MnF2 between 4 K and room temperature. We show that the phonon spectrum undergoes a strong renormalization at TN. The ab-initio calculation we performed on this compound…

Materials Science · Physics 2010-10-20 R. Schleck , Y. Nahas , R. P. S. M. Lobo , J. Varignon , M. B. Lepetit , C. S. Nelson , R. L. Moreira

Motivated by the absence of experimental superconductivity in the metallic Pm-3n phase of AlH3 despite the predictions, we reanalyze its vibrational and superconducting properties at pressures above 99 GPa making use of first-principles…

Superconductivity · Physics 2021-05-05 Pugeng Hou , Francesco Belli , Raffaello Bianco , Ion Errea

We report total energy calculations for different crystal structures of NaNbO$_3$ over a range of unit cell volumes using the all-electron full-potential (L)APW method. We employed both the local-density approximation (LDA) and the Wu-Cohen…

Materials Science · Physics 2015-05-30 R. Machado , M. Sepliarsky , M. G. Stachiotti

We used first-principles methods to perform a systematic search for potentially-stable phases of multiferroic BiFeO3. We considered a simulation cell compatible with the atomic distortions that are most common among perovskite oxides, and…

Materials Science · Physics 2013-05-29 Oswaldo Diéguez , O. E. González-Vázquez , Jacek C. Wojdeł , Jorge Íñiguez

First principles density functional theory (DFT) simulations of antiferroelectric (AFE) PbZrO$_3$ and PbHfO$_3$ reveal a dynamical instability in the phonon spectra of their purported low temperature $Pbam$ ground states. This instability…