相关论文: Kinetic pathways of coesite densification from met…

The Si(001) surface subjected to different treatments in ultrahigh vacuum molecular beam epitaxy chamber for SiO$_2$ film decomposition has been in situ investigated by reflected high energy electron diffraction (RHEED) and high resolution…

We report high pressure structural phase transformation sequence in a layered Iron-based superconducting compound FeSe0.3Te0.7 to 31 GPa at room temperature. The ambient pressure PbO type tetragonal phase (Space Group - P4/nmm) transforms…

Transport and magnetic studies of PbTaSe$_2$ under pressure suggest existence of two superconducting phases with the low temperature phase boundary at $\sim 0.25$ GPa that is defined by a very sharp, first order, phase transition. The first…

While the tetragonal antiferro-electrically distorted (AFD) phase with space group $I4/mcm$ is well known for SrTiO$_3$ to occur below 105 K, there are also some hints in literature of an orthorhombic phase, either at lower temperature at…

FeSe with the PbO structure is a key member of the family of new high-$T_c$ iron pnictide and chalcogenide superconductors, as while it possesses the basic layered structural motif of edge-sharing distorted FeSe$_4$ tetrahedra, it lacks…

Changes in atomic coordination numbers at high pressures are fundamental to condensed-matter physics because they initiate the emergence of unexpected structures and phenomena. Silicon is capable of forming eight-, nine-, and…

Iron-chalcogenide superconductor Fe$_{1.03}$Se$_{0.5}$Te$_{0.5}$ has been investigated under high pressure using synchrotron based x-ray diffraction and mid-infrared reflectance measurements at room temperature. Pressure dependence of the…

The effects of pressure on the crystal structure of the three known polymorphs of magnesium sulfate have been theoretically study by means of DFT calculations up to 45 GPa. We determined that at ambient conditions gamma MgSO4 is an unstable…

We report an {\it ab initio} simulation study of changes in structural and dynamic properties of liquid Si at 7 pressures ranging from 10.2 GPa to 24.3 GPa along the isothermal line 1150~K, which is above the minimum of the melting line.…

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…

Simultaneous high pressure x-ray diffraction and electrical resistance measurements have been carried out on a PbO type {\alpha}-FeSe0.92 compound to a pressure of 44 GPa and temperatures down to 4 K using designer diamond anvils at…

We study the structural evolution of Sr$_3$Ir$_2$O$_7$ as a function of pressure using x-ray diffraction. At a pressure of 54 GPa at room temperature, we observe a first-order structural phase transition, associated with a change from…

Concurrent molecular dynamics simulations and ab initio calculations show that densification of silica under pressure follows a ubiquitous two-stage mechanism. First, anions form a close-packed sub-lattice, governed by the strong repulsion…

Room temperature angle-dispersive x-ray diffraction measurements on zircon-type EuVO4, LuVO4, and ScVO4 were performed up to 27 GPa. In the three compounds we found evidence of a pressure-induced structural phase transformation from zircon…

Uranium ditelluride (UTe$_2$) has attracted recent interest due to its unique superconducting properties, which include the potential for a topological odd-parity superconducting state. Recently, ac-calorimetry measurements under pressure…

The crystal structure of solid oxygen at low temperatures and at pressures up to 7 GPa is studied by theoretical calculations. In the calculations, the adiabatic potential of the crystal is approximated by a superposition of pair-potentials…

The work discusses specifics of phase transitions for metastable states of substances. The objects of condensed media physics are primarily equilibrium states of substances with metastable phases viewed as an exception, while the…

AgClO4 has been studied under compression by x-ray diffraction and density functional theory calculations. Experimental evidence of a structural phase transition from the tetragonal structure of AgClO4 to an orthorhombic barite-type…

Classical molecular-dynamics simulations have been carried out to investigate densification mechanisms in silicon dioxide thin films deposited on an amorphous silica surface, according to a simplified ion-beam assisted deposition (IBAD)…

Single crystals of XPt$_{5}$P (X = Al, Ga, and In) were grown from a Pt-P solution at high temperatures, and ambient-pressure measurements of temperature-dependent magnetization, resistivity, and X-ray diffraction were made. Also, the…