Related papers: High-pressure phase relations in Zn2SiO4 system: A…
We report on the electronic and optical properties of two theoretically predicted stable spinel compounds of the form ZnB2O4, where B = Ni or Cu; neither compound has been previously synthesized, so we compare them to the previously studied…
The authors of the Letter PRL 89, 017004 (2002) predict nontrivial flux lattice structures in UPt3 in vicinity of the superconducting transition between the A and B phases for low magnetic fields, an important conclusion for motivating…
Supersolid phases, in which a superfluid component coexists with conventional crystalline long range order, have recently attracted a great deal of attention in the context of both solid helium and quantum spin systems. Motivated by recent…
Angle-dispersive x-ray diffraction (ADXRD) and x-ray absorption near edge structure (XANES) measurements have been performed in the AWO4 tungstates CaWO4 and SrWO4 under high pressure up to approximately 20 GPa. Similar phase transitions…
The Kitaev model of spin-1/2 on a honeycomb lattice supports degenerate topological ground states and may be useful in topological quantum computation. Na$_{2}$IrO$_{3}$ with honeycomb lattice of Ir ions have been extensively studied as…
We investigate a highly frustrated spin-1 model on the triangular lattice, with nearest- and next-nearest-neighbor antiferromagnetic $S\cdot S$ interactions and nearest-neighbor $(S\cdot S)^2$ interactions. Using the density matrix…
We study the dynamics of inorganic antiferroelectric nanoclusters formed during an order-disorder transition and demonstrate the coexistence of the two phases in a region of 2-3 K around the transition temperature TN~215 K. Single crystals…
The temperature dependence of eigenfrequencies and intensities of the IR active modes has been investigated for the antiferromagnetic chromium spinel compounds CdCr2O4, ZnCr2O4, ZnCr2S4, ZnCr2Se4, and HgCr2S4 by IR spectroscopy for…
Using a novel electrochemical phase-field model, we question the common belief that LixFePO4 nanoparticles separate into Li-rich and Li-poor phases during battery discharge. For small currents, spinodal decomposition or nucleation leads to…
The structure of solid oxygen has been studied at pressures from 50 to 140~GPa using static structure search methods and molecular dynamics simulations with density functional theory and a hybrid exchange functional. Several crystalline…
The behavior of LuLiF4 sheelite (I41/a, Z = 4) under hydrostatic pressure was investigated by means of the first principles calculations. The ferroelastic phase transition from the tetragonal structure of LuLiF4 to fergusonite structure…
We report our first-principles investigations on three polytypes of BaTiO3 (BTO): a paraelectric phase with cubic Pm-3m structure and two ferroelectric (FE) phases with tetragonal P4mm and rhombohedral R3m structures. We compared the…
A three-component Ginzburg-Landau theory for a triplet pairing is developed to understand the observed multiple phases in a new superconductor UTe$_2$ under pressure. Near the critical pressure $P_{\rm cr}$=0.2GPa where all components are…
We present first-principles calculations of the structural phase behavior of the [1:1] \pzta\ superlattice and the \ptoa\ and \pzoa\ parent compounds as a function of in-plane epitaxial strain. A symmetry analysis is used to identify the…
We present our theoretical results on the mechanism of two transitions in vanadium spinel oxides $A$V$_2$O$_4$ ($A$=Zn, Mg, or Cd) in which magnetic V cations constitute a geometrically-frustrated pyrochlore structure. We have derived an…
In this lecture we review high-pressure phase transition sequences exhibited by simple elements, looking at the examples of the main group I, II, IV, V, and VI elements. General trends are established by analyzing the changes in…
Three Mo-based transition metal dichalcogenides MoS$_2$, MoSe$_2$ and MoTe$_2$ share at ambient conditions the same structure 2H$_c$, consisting of layers where Mo atoms are surrounded by six chalcogen atoms in trigonal prism coordination.…
The high pressure phase diagrams of TaAs family (NbP, NbAs, TaP and TaAs) are explored systematically using crystal structure search together with first-principles calculations. Our calculations show that NbAs and TaAs have similar phase…
We have carried out the powder x-ray diffraction and dielectric studies on multiferroic particulate composite xNi0.9Zn0.1Fe2O4/(1-x)PbZr0.52Ti0.48O3 with x=0.15, 0.30, 0.45, 0.60, 0.75 and 0.90 to explore the structural and ferroelectric…
We have investigated the group 14 nitrides (M$_3$N$_4$) in the spinel phase ($\gamma$-M$_3$N$_4$ with M= C, Si, Ge and Sn) and $\beta$ phase ($\beta$-M$_3$N$_4$ with M= Si, Ge and Sn) using density functional theory with the local density…