Related papers: A High Pressure Distorted a-Uranium (Pnma) Structu…
In this paper we propose a new pseudo-phase crystal structure, based on an orthorhombic distortion of the diamond structure, for the ground-state $\alpha$-phase of plutonium. Electronic-structure calculations in the generalized-gradient…
Structural changes of Li2C2 under pressure were studied by synchrotron x-ray diffraction in a diamond anvil cell under hydrostatic conditions and by using evolutionary search methodology for crystal structure prediction. We show that the…
Amorphous phosphorus (a-P) has long attracted interest because of its complex atomic structure, and more recently as an anode material for batteries. However, accurately describing and understanding a-P at the atomistic level remains a…
Using $\textit{ab-initio}$ crystal structure prediction we study the high-pressure phase diagram of $\textit{A}BiO_3$ bismuthates ($A$=Ba, Sr, Ca) in a pressure range up to 100$~$GPa. All compounds show a transition from the low-pressure…
The structural behavior of UO2 under high pressure up to 300GPa has been studied by first-principles calculations with LSDA+U approximation. The results show that a pressure-induced structural transition to the cotunnite-type (orthorhombic…
The rare earth metal praseodymium (Pr) transforms from the d-fcc crystal structure (Pr-III) to {$\alpha$}-U one (Pr-IV) at 20 GPa with a large volume collapse (${\rm\Delta} V/V$ = 0.16), which is associated with the valence change of the Pr…
The equation of state, structural behavior and phase stability of {\alpha}-uranium have been investigated up to 1.3 TPa using density functional theory, adopting a simple description of electronic structure that neglects the spin-orbit…
Manganese, in the a-Mn structure, has been studied using synchrotron powder x-ray diffraction in a diamond anvil cell up to 220 GPa at room temperature combined with density functional calculations (DFT). The experiment reveals an extended…
Recent experimental results on two hcp phases of barium under high pressure show interesting variation of the lattice parameters. They are here interpreted in terms of electronic structure calculation by using the LMTO method and…
We studied the crystal and magnetic structure of Ca2RuO4 by different diffraction techniques under high pressure. The observed first order phase transition at moderate pressure (0.5 GPa) between the insulating phase and the metallic high…
The pressure-induced structural phase transition in the intermediate-valence compound CeNi has been investigated by X-ray and neutron powder diffraction techniques. For the first time it is shown that the structure of the pressure-induced…
Metastable aluminum-alloyed $\delta$-plutonium shrinks rapidly and pure $\alpha$-plutonium swells rapidly at 4 K. At ambient temperature alloyed $\delta$-plutonium swells about $10^{-3}$ as fast as it shrinks at 4 K, but its bulk density…
Uranium manganese germanide, UMn2Ge2, crystallizes in body-centered tetragonal ThCr2Si2 structure with space group I4/mmm, a = 3.993A and c = 10.809A under ambient conditions. Energy dispersive X-ray diffraction was used to study the…
High pressure x-ray diffraction (XRD) measurements on RMnO3 (R=Dy, Ho and Lu) reveals that varying structural changes occurs for different R ions. Large lattice changes (orthorhombic strain) occur in DyMnO3 and HoMnO3 while the Jahn-Teller…
At high pressure, the typical behavior of elements dictated by the periodic table - including oxidation numbers, stoichiometries in compounds, and reactivity, to name but a few - is altered dramatically. As pressure is applied, the…
Synchrotron x-ray diffraction experiments have been carried out on Eu metal at ambient temperature to pressures as high as 92 GPa (0.92 Mbar). Following the well-known bcc-to-hcp transition at 12 GPa, a mixed phase region is observed from…
There has been a recent controversy about the high pressure polymorphism of Hafnium (Hf). Unlike, the earlier known {\alpha} $\rightarrow$ {\omega} structural transition at 38 $\pm$ 8 GPa, Hrubiak et al (2012) did not observe it till 51…
One of the most challenging problems in understanding the structural phase transformations in Pu is to determine the energetically favored, continuous atomic pathways from one crystal symmetry to another. This problem involves enumerating…
In-situ high pressure single crystal X-ray diffraction study reveals that the quantum material CaMn$_2$Bi$_2$ undergoes a unique plane to chain structural transition between 2 and 3 GPa, accompanied by a large volume collapse. CaMn2Bi2…
Void swelling can develop in materials under persistent irradiation when non-equilibrium vacancy and self-interstitial populations migrate under sufficiently asymmetric interaction biases. In conventional metals, the propensity is…