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We present in-situ x-ray diffraction and velocity measurements of Fe$_2$O$_3$ under laser shock compression at pressures between 38-116 GPa. None of the phases reported by static compression studies were observed. Instead, we observed an…

We employ a combination of the \emph{ab initio} band structure methods and dynamical mean-field theory to determine the electronic structure and phase stability of paramagnetic FeO at high pressure and temperature. Our results reveal a…

Strongly Correlated Electrons · Physics 2015-09-18 I. Leonov

We report here the first equation of state measurements of Fe$_2$O$_3$ obtained with laser-driven shock compression. The data are in excellent agreement with previous dynamic and static compression measurements at low pressure, and extend…

FeO (w\"ustite), which exhibits complex electronic and structural properties with increasing pressure and temperature, is a key mineralogical phase for understanding deep planetary interiors. However, direct measurements of its spin state…

The partial density of vibrational states has been measured for Fe in compressed FeO (w\"ustite) using nuclear resonant inelastic x-ray scattering. Substantial changes have been observed in the overall shape of the density of states close…

Rare earth (R) orthoferrites RFeO_3 exhibit large volume transitions associated with a spin collapse. We present here ab initio calculations on LuFeO_3. We show that taking into account the strong correlation among the Fe-3d electrons is…

Strongly Correlated Electrons · Physics 2009-04-30 Donat J. Adams , Bernard Amadon

We present measurements on Fe$_2$O$_3$ amorphization and melt under laser-driven shock compression up to 209(10) GPa via time-resolved in situ x-ray diffraction. At 122(3) GPa, a diffuse signal is observed indicating the presence of a…

Structural, magnetic and electrical-transport properties of {\alpha}-LiFeO2, crystallizing in the rock salt structure with random distribution of Li and Fe ions, have been studied by synchrotron X-ray diffraction, 57Fe M\"ossbauer…

Strongly Correlated Electrons · Physics 2017-09-29 Samar Layek , Eran Greenberg , Weiming Xu , Gregory Kh. Rozenberg , Moshe P. Pasternak , Jean-Paul Itié , Dániel G. Merkel

Fe-bearing MgO [(Mg$_{1-x}$Fe$_x$)O] is considered a major constituent of terrestrial exoplanets. Crystallizing in the B1 structure in the Earth's lower mantle, (Mg$_{1-x}$Fe$_x$)O undergoes a high-spin ($S=2$) to low-spin ($S=0$)…

Materials Science · Physics 2022-05-20 Han Hsu , Koichiro Umemoto

We report a detail theoretical study of the electronic structure and phase stability of transition metal oxides MnO, FeO, CoO, and NiO in their paramagnetic cubic B1 structure by employing dynamical mean-field theory of correlated electrons…

Strongly Correlated Electrons · Physics 2016-10-26 I. Leonov , L. Pourovskii , A. Georges , I. A. Abrikosov

SrMoO4 was studied under compression up to 25 GPa by angle-dispersive x-ray diffraction. A phase transition was observed from the scheelite-structured ambient phase to a monoclinic fergusonite phase at 12.2(9) GPa with cell parameters a =…

Materials Science · Physics 2008-02-04 Daniel Errandonea , Ravhi S. Kumar , Xinghua Ma , Chaoyang Tu

The Local Density Approximation combined with Dynamical Mean-Field Theory (LDA+DMFT method) is applied to the study of the paramagnetic and magnetically ordered phases of hematite Fe$_2$O$_3$ as a function of volume. As the volume is…

Strongly Correlated Electrons · Physics 2009-04-07 J. Kunes , Dm. M. Korotin , M. A. Korotin , V. I. Anisimov , P. Werner

X-ray diffraction pressure studies at room temperature demonstrate that the spinel FeAl$_{2}$O$_{4}$ transforms to a tetragonal phase at ~18 GPa. This tetragonal phase has a highly irregular unit-cell volume versus pressure dependence up to…

Strongly Correlated Electrons · Physics 2018-09-26 W. M. Xu , G. R. Hearne , S. Layek , D. Levy , M. P. Pasternak , G. Kh. Rozenberg , E. Greenberg

Electrical conductivity of FeO was measured up to 141 GPa and 2480 K in a laserheated diamond-anvil cell. The results show that rock-salt (B1) type structured FeO metallizes at around 70 GPa and 1900 K without any structural phase…

Materials Science · Physics 2015-06-03 Kenji Ohta , R. E. Cohen , Kei Hirose , Kristjan Haule , Katsuya Shimizu , Yasuo Ohishi

We report synchrotron x-ray powder diffraction measurements of Ce0.8La0.1Th0.1 subject to pulsed magnetic fields as high as 28 Tesla. This alloy is known to exhibit a continuous volume collapse on cooling at ambient pressure, which is a…

Strongly Correlated Electrons · Physics 2012-07-16 J. P. C. Ruff , Z. Islam , R. K. Das , H. Nojiri , J. C. Cooley , C. H. Mielke

In this work we present an extensive study of glassy GeO$_2$ under laser induced dynamic compression. New VISAR and SOP data provide the extension of Hugoniot EoS up to the TPa range for this material including temperature measurements.…

Quantum molecular dynamic simulations are introduced to study the shock compressed oxygen. The principal Hugoniot points derived from the equation of state agree well with the available experimental data. With the increase of pressure,…

Materials Science · Physics 2015-05-14 Cong Wang , Ping Zhang

We report the observation of the pressure-induced high-spin to low-spin transition in FeS using new high-pressure synchrotron x-ray emission spectroscopy techniques. The transition is evidenced by the disappearance of the low-energy…

Gadolinium has long been believed to undergo a high pressure phase transition with a volume collapse around 5%. Theoretical explanations have focused on the idea of electrons transferring from the extended s-orbital to the compact…

Materials Science · Physics 2021-09-10 Qingchen Li , Hossein Ehteshami , Keith Munro , Malcolm I McMahon , Graeme J. Ackland

The pressure evolution of the local structure of Fe2O3 hematite has been determined for the first time by extended x-ray absorption fine structure up to 79 GPa. The comparison to the different high-pressure forms proposed in the literature…

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