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Related papers: Intermediate spin state and the B1-B2 transition i…

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Ferropericlase, (Mg,Fe)O, is the second-most abundant mineral of the Earth's lower mantle. With increasing pressure, the Fe ions in the material begin to collapse from a magnetic to non-magnetic spin state. We present a finite-temperature…

Materials Science · Physics 2015-06-23 Eero Holmstrom , Lars Stixrude

Spin crossover of iron is of central importance in solid Earth geophysics. It impacts all physical properties of minerals that altogether constitute $\sim 95$ vol\% of the Earth's lower mantle: ferropericlase [(Mg,Fe)O] and Fe-bearing…

Strongly Correlated Electrons · Physics 2015-06-23 Han Hsu , Renata M. Wentzcovitch

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

Ferropericlase, (Mg,Fe)O is one of the most abundant minerals of the Earth's lower mantle. The high-spin (HS) to low-spin (LS) transition in the Fe2+ ions can dramatically alter the physical and chemical properties of (Mg,Fe)O in the deep…

Ferropericlase (Fp), (Mg$_\mathrm{1-x}$Fe$_\mathrm{x}$)O, is the second most abundant phase in the Earths lower mantle. At relevant pressure-temperature conditions, iron in Fp undergoes a high spin (HS), S=2, to low spin (LS), S=0, state…

Geophysics · Physics 2020-10-28 Michel L. Marcondes , Fawei Zheng , Renata M. Wentzcovitch

Ferropericlase (Mg,Fe)O is a major lower mantle mineral, and studying its properties is a fundamental step toward understanding the Earth's interior. Here, we performed a first-principles investigation on the properties of iron as an…

Materials Science · Physics 2013-04-09 R. Larico , L. V. C. Assali , J. F. Justo

We present LDA+$U_{sc}$ calculations of high-spin (HS) and low-spin (LS) states in ferropericlase (fp) with an iron concentration of 18.75$\%$. The Hubbard parameter $U$ is determined self-consistently with structures optimized at arbitrary…

Geophysics · Physics 2022-04-12 Yang Sun , Jingyi Zhuang , Renata M. Wentzcovitch

Using density functional theory plus Hubbard $U$ calculations, we show that the ground state of (Mg,Fe)(Si,Fe)O$_3$ perovskite, a major mineral phase in the Earth's lower mantle, has high-spin ferric iron ($S=5/2$) at both the dodecahedral…

Geophysics · Physics 2015-05-27 Han Hsu , Peter Blaha , Matteo Cococcioni , Renata M. Wentzcovitch

Earth's lower mantle is generally believed to be seismically and chemically homogeneous because most of the key seismic parameters can be explained using a simplified mineralogical model at expected press-temperature conditions. However,…

Materials Science · Physics 2017-04-06 Shenzhen Xu , Jung-Fu Lin , Dane Morgan

The results of magnetic and spectral properties calculation for paramagnetic phase of ferropericlase (Fe$_{1/4}$Mg$_{3/4}$)O at ambient and high pressures are reported. Calculations were performed by combined Local Density Approximation +…

Materials Science · Physics 2014-11-21 N. A. Skorikov , A. O. Shorikov , S. L. Skornyakov , M. A. Korotin

Iron-bearing oxides undergo a series of pressure-induced electronic, spin and structural transitions that can cause seismic anomalies and dynamic instabilities in Earth's mantle and outer core. We employ x-ray diffraction and x-ray emission…

Strongly Correlated Electrons · Physics 2023-07-10 E. Greenberg , R. Nazarov , A. Landa , J. Ying , R. Q. Hood , B. Hen , R. Jeanloz , V. B. Prakapenka , V. V. Struzhkin , G. Kh. Rozenberg , I. Leonov

At extreme pressures of approximately 500 GPa, conditions characteristic of the deep interiors of super-Earths, the combination of NaCl-type MgO and post-perovskite-type MgSiO3 (PPv) has been reported to produce a post-PPv phase of Mg2SiO4…

Materials Science · Physics 2025-04-10 Tianqi Wan , Yang Sun , Renata M. Wentzcovitch

The structural, electronic and magnetic properties of Fe7S8 material have been studied within the framework of the ab-initio calculations, the mean field approximation (MFA) and Monte Carlo simulation (MCS). Our study shows that two forms…

Materials Science · Physics 2020-12-09 S. Benyoussef , Y. EL Amraoui , H. Ez-Zahraouy , D. Mezzane , Z. Kutnjak , I. A. Luk'yanchuk , M. EL Marssi

We present a detailed theoretical study of the electronic, magnetic, and structural properties of magnesiow\"ustite Fe$_{1-x}$Mg$_x$O with $x$ in the range between 0$-$0.875 using a fully charge self-consistent implementation of the density…

Strongly Correlated Electrons · Physics 2017-08-24 I. Leonov , A. Ponomareva , R. Nazarov , I. A. Abrikosov

The magnetic properties of the double perovskite oxide $Sr_{2}$FeMo$O_{6}$ are analyzed using a mixed-spin Ising model with spins $\left( \frac{1}{2},\frac{5}{2}\right) $ in the presence of a random crystal field $\Delta$ and exchange…

Statistical Mechanics · Physics 2025-03-10 Said Khaireddine , Redouane Assad , Mohammed El Falaki , Rachid Ahl Lamara , Lalla Btissam Drissi

We study the magnetic, structural, and electronic properties of the recently discovered iron- based superconductor BaFe2S3 based on density functional theory with the generalized gradient approximation. The calculations show that the…

Strongly Correlated Electrons · Physics 2015-08-19 Michi-To Suzuki , Ryotaro Arita , Hiroaki Ikeda

We perform density functional calculations of the equilibrium 57Fe/54Fe ratios for ferrous iron dissolved in periclase and MgSiO3 perovskite at the pressures and temperatures of the Earth's mantle. Pressure increases the partitioning of…

Materials Science · Physics 2008-07-31 James R. Rustad , Piotr Zarzycki , Maryali P. Sauceda , Qing-zhu Yin

We predict an unconventional magnetic ground state in A$_y$Fe$_{1.6}$Se$_2$ with $\sqrt{5}\times\sqrt{5}$ Fe-vacancy superstructure under hydraulic external pressure based on first-principles simulations. While the Fe-vacancy ordering…

Superconductivity · Physics 2011-08-30 Chao Cao , Minghu Fang , Jianhui Dai

The Fe electronic structure and magnetism in (i) monoclinic Ca$_2$FeReO$_6$ with a metal-insulator transition at $T_{MI} \sim 140$ K and (ii) quasi-cubic half-metallic Ba$_2$FeReO$_6$ ceramic double perovskites are probed by soft x-ray…

Strongly Correlated Electrons · Physics 2019-05-14 E. Granado , J. C. Cezar , C. Azimonte , J. Gopalakrishnan , K. Ramesha
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