相关论文: New Phases of Solid Nitrogen

Phase I of hydrogen has several peculiarities. Despite having a close-packed crystal structure, it is less dense than either the low temperature Phase II or the liquid phase. At high pressure, it transforms into either phase III or IV,…

Nitrides in many ways are fascinating since they often appear as superconductors, high energy density and hard materials. Though there exist a large variety of nitrides, noble gas nitrides are long missing in nature. Pursuit of noble gas…

Ferroelectric nematic liquid crystals represent not only interesting fundamental science, but they also hold promise for storage capacitors with high power density or new information display technology having sub-millisecond switching. In…

A system of hard rigid rods of length $k$ on hypercubic lattices is known to undergo two phases transitions when chemical potential is increased: from a low density isotropic phase to an intermediate density nematic phase, and on further…

The phase relations in boron have been investigated at high pressure and high temperature using a multianvil apparatus, and the quenched sample has been analyzed by x-ray diffraction, Raman spectra and transmission electron microscopy. We…

Black phosphorus nitrogen (BP-N) is an attractive high-energy-density material. However, high-pressure synthesized BP-N will decompose at low-pressure and cannot be quenched to ambient conditions. Finding a method to stabilize it at 0 GPa…

Sodium niobate (NaNbO3) exhibits most complex sequence of structural phase transitions in perovskite family and therefore provides as excellent model system for understanding the mechanism of structural phase transitions. We report…

In situ high-pressure energy dispersive x-ray diffraction experiments on polycrystalline powder TiN with NaCl-type structure have been conducted with the pressure up to 30.1 GPa by using the diamond anvil cell instrument with synchrotron…

We study an experimental system of hard granular squares in two dimensions, energized by vibration. The interplay of order in the orientations and positions of anisotropic particles allows for a rich set of phases. We measure the structure…

We report the evolution of charge density wave states under pressure for two NbS3 phases triclinic (phase I) and monoclinic (phase II) at room temperature. Raman and X-ray diffraction (XRD) techniques are applied. The x-ray studies on the…

Synchrotron X-ray diffraction and Raman spectroscopy have been used to study chemical reactions of molecular hydrogen (H2) with sulfur (S) at high pressures. We find theoretically predicted Cccm and Im-3m H3S to be the reaction products at…

We systematically explored the phase behavior of the hard-core two-scale ramp model suggested by Jagla[E. A. Jagla, Phys. Rev. E 63, 061501 (2001)] using a combination of the nested sampling and free energy methods. The sampling revealed…

A new class of strongly infrared active structures is identified for phase III of compressed molecular H2 by constant-pressure ab initio molecular dynamics and density-functional perturbation calculations. These are planar quadrupolar…

Contradictory results of high-pressure studies in cubic bixbyite-type indium oxide (c-In2O3) at room temperature (RT) have motivated us to perform high-pressure powder x-ray diffraction and Raman scattering measurements in this material. On…

A previously unknown thermodynamically stable high-pressure phase of BeF$_{2}$ has been predicted using the evolutionary algorithm USPEX. This phase occurs in the pressure range 18-27 GPa. Its structure has $C2/c$ space group symmetry and…

The discovery of ambient superconductivity would mark an epochal breakthrough long-awaited for over a century, potentially ushering in unprecedented scientific and technological advancements. The recent findings on high-temperature…

We present a stability analysis of the 2D t-t' Hubbard model on a square lattice for various values of the next-nearest-neighbor hopping t' and electron concentration. Using the free energy expression, derived by means of the flow equations…

Cobalt nitride (Co-N) thin films prepared using a reactive magnetron sputtering process by varying the relative nitrogen gas flow (\pn) are studied in this work. As \pn~increases, Co(N), \tcn, Co$_3$N and CoN phases are formed. An…

The high-pressure behavior of monoclinic VO$_2$ is revisited by a combination of Raman spectroscopy and X-ray diffraction on a single crystal under hydrostatic conditions at room temperature. A soft mode is observed up to P$_c$ = 13.9(1)…

Laser nitriding represents a versatile approach for tailoring the surface properties of metals. Up to now, its effect on the superconducting response of niobium nitrides remains largely unexplored. In this work, the nitriding process of…