English
Related papers

Related papers: Polymorphism in $\alpha$-sexithiophene crystals: R…

200 papers

Positional polymorphism in solids refers to locally disordered unit cells that, on average, reproduce the high-symmetry structures observed in diffraction experiments. Standard theories of electron-phonon interactions fail to describe the…

We introduce a computational method to discover polymorphs in molecular crystals at finite temperature. The method is based on reproducing the crystallization process starting from the liquid and letting the system discover the relevant…

Chemical Physics · Physics 2020-04-10 Pablo M. Piaggi , Michele Parrinello

Due to its high electrical conductivity and excellent transmittance at terahertz frequencies, graphene is a promising candidate as transparent electrodes for terahertz devices. We demonstrate a liquid crystal based terahertz phase shifter…

We investigate the high-pressure phase transitions in BiFeO3 by single crystal and powder x-ray diffraction, as well as single crystal Raman spectroscopy. Six phase transitions are reported in the 0-60 GPa range. At low pressures, up to 15…

The ability to reliably predict the structures and stabilities of a molecular crystal and its polymorphs without any prior experimental information would be an invaluable tool for a number of fields, with specific and immediate applications…

The temperature-dependent electronic structures of heavy fermion compound CeB$_{6}$ are investigated thoroughly by means of the combination of density functional theory and single-site dynamical mean-field theory. The band structure,…

Strongly Correlated Electrons · Physics 2017-05-03 Haiyan Lu , Li Huang

Phase change materials can be reversibly switched between amorphous and crystalline states and often show strong contrast in the optical and electrical properties of these two phases. They are now in widespread use for optical data storage,…

Mesoscale and Nanoscale Physics · Physics 2012-11-06 Nicholas P. Breznay , Hanno Volker , Alexander Palevski , Riccardo Mazzarello , Aharon Kapitulnik , Matthias Wuttig

We investigate the finite-temperature phase diagram of polar molecules confined in a quasi-two-dimensional geometry by a harmonic potential along the polarization axis. We employ Quantum Monte Carlo simulations to explore the strongly…

Quantum Gases · Physics 2026-05-19 Vinicius Zampronio , Matteo Ciardi , Fabio Cinti

"Fluid polyamorphism" is the existence of different condensed amorphous states in a single-component fluid. It is either found or predicted, usually at extreme conditions, for a broad group of very different substances, including helium,…

The charge transfer compound (BEDT-TTF)$_2$Ag(CF$_3$)$_4$(TCE) crystallizes in three polymorphs with different alternating layers: While a phase with a $\kappa$ packing motif has a low superconducting transition temperature of $T_c=2.6$ K,…

Strongly Correlated Electrons · Physics 2015-06-18 Michaela Altmeyer , Roser Valenti , Harald O. Jeschke

ErAl$_3$ can form in either a trigonal ($\alpha$) or cubic ($\beta$) polymorph and this paper investigates the physical properties of these polymorphs through characterizations of single crystals grown in an aluminum flux. We demonstrate…

Strongly Correlated Electrons · Physics 2025-07-15 Karolina Gornicka , Brenden R. Ortiz , Andrew D. Christianson , Andrew F. May

Single crystal synchrotron X-ray diffraction as a function of temperature and pressure has revealed a complex biphase mixture in superconducting FeSe. Based on our experimental results we construct a phase diagram where structural behavior…

Superconductivity · Physics 2017-08-02 V. Svitlyk , M. Raba , V. Dmitriev , P. Rodiere , P. Toulemonde , D. Chernyshov , M. Mezouar

We propose an experimental scheme to effectively assemble chains of dipolar gases with an uniform length in a multi-layer system. The obtained dipolar chains can form a chain crystal with the system temperature easily controlled by the…

Quantum Gases · Physics 2015-06-19 Jhih-Shih You , Daw-Wei Wang

The paper presents an analysis of mechanical, structural, thermophysical and spectral properties of solid methane in temperature interval $0.5T_{tr} -T_{tr}$ ($T_{tr}$ is the triple point temperature) under equilibrium vapor pressure. It is…

Materials Science · Physics 2014-04-30 A. V. Leont'eva , A. Yu. Prokhorov , A. Yu. Zakharov , A. I. Erenburg

Phase transitions in metastable $\alpha$-, $\kappa(\epsilon)$-, and $\gamma$-Ga$_2$O$_3$ films to thermodynamically stable $\beta$-Ga$_2$O$_3$ during annealing in air, N$_2$, and vacuum have been systematically investigated via in-situ…

Materials Science · Physics 2024-05-02 J. Tang , K. Jiang , P. Tseng , R. C. Kurchin , L. M. Porter , R. F. Davis

Near 20.48K and in the temperature range 60--70K, anomalous behavior of thermodynamic, spectral, plastic, elastic and other properties of solid methane is observed. The anomalies in the vicinity of 20.48K are due to the phase $\alpha-\beta$…

Materials Science · Physics 2017-09-12 A. V. Leont'eva , A. Yu. Zakharov , A. Yu. Prokhorov

We present temperature-dependent single-crystal diffraction results on seven antifluorite-type $A_2MeX_6$ compounds with $Me$=Os or Ir: K$_2$OsCl$_6$, $A_2$OsBr$_6$ with $A$=K, Rb, Cs and NH$_4$, and K$_2$Ir$X_6$ with $X$=Cl and Br. The…

Materials Science · Physics 2024-03-19 A. Bertin , L. Kiefer , P. Becker , L. Bohatý , M. Braden

The low-temperature thermal conductivity in polycrystalline graphene is theoretically studied. The contributions from three branches of acoustic phonons are calculated by taking into account scattering on sample borders, point defects and…

Materials Science · Physics 2015-06-05 D. V. Kolesnikov , V. A. Osipov

We have discovered a new compound of the composition ScPd2Al3 crystallizing in unknown structure type. Moreover, ScPd2Al3 reveals polymorphism. We have found an orthorhombic crystal structure at room temperature and a high temperature cubic…

Results of X-ray diffraction experiments on solid oxygen at low temperature and at pressures up to 10 GPa are presented.A careful sample preparation and annealing around 240 K allowed to obtain very good diffraction patterns in the…

Materials Science · Physics 2009-11-07 Federico A. Gorelli , Mario Santoro , Lorenzo Ulivi , Michael Hanfland