1
|
Luo J, Zhang Q, Lin J, Ni Y, Wang H, Tang Y, Lan M. TaF 4: A Novel Two-Dimensional Antiferromagnetic Material with a High Néel Temperature Investigated Using First-Principles Calculations. MATERIALS (BASEL, SWITZERLAND) 2024; 17:2780. [PMID: 38894043 PMCID: PMC11173987 DOI: 10.3390/ma17112780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Revised: 05/28/2024] [Accepted: 05/31/2024] [Indexed: 06/21/2024]
Abstract
The structural, electronic, and magnetic properties of a novel two-dimensional monolayer material, TaF4, are investigated using first-principles calculations. The dynamical and thermal stabilities of two-dimensional monolayer TaF4 were confirmed using its phonon dispersion spectrum and molecular dynamics calculations. The band structure obtained via the high-accuracy HSE06 (Heyd-Scuseria-Ernzerhof 2006) functional theory revealed that monolayer two-dimensional TaF4 is an indirect bandgap semiconductor with a bandgap width of 2.58 eV. By extracting the exchange interaction intensities and magnetocrystalline anisotropy energy in a J1-J2-J3-K Heisenberg model, it was found that two-dimensional monolayer TaF4 possesses a Néel-type antiferromagnetic ground state and has a relatively high Néel temperature (208 K) and strong magnetocrystalline anisotropy energy (2.06 meV). These results are verified via the magnon spectrum.
Collapse
Affiliation(s)
- Jia Luo
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education of China, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610032, China
| | - Qingkai Zhang
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education of China, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610032, China
| | - Jindong Lin
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education of China, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610032, China
| | - Yuxiang Ni
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education of China, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610032, China
| | - Hongyan Wang
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education of China, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610032, China
| | - Yongliang Tang
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education of China, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610032, China
| | - Mu Lan
- College of Optoelectronic Engineering, Chengdu University of Information Technology, Chengdu 610103, China
| |
Collapse
|
2
|
Li C, An Y. Two-dimensional ferromagnetic semiconductors of rare-earth Janus 2H-GdIBr monolayers with large valley polarization. NANOSCALE 2023; 15:8304-8312. [PMID: 37082903 DOI: 10.1039/d2nr06654h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Based on a rare-earth Gd atom with 4f electrons, through first-principles calculations, we demonstrate that a Janus 2H-GdIBr monolayer exhibits an intrinsic ferromagnetic (FM) semiconductor character with an indirect band gap of 0.75 eV, a high Curie temperature Tc of 260 K, a significant magnetic moment of 8μB per f.u. (f.u. = formula unit), in-plane magnetic anisotropy (IMA) and a large spontaneous valley polarization of 118 meV. The MAE, inter-atomic distance or angle, and Tc can be efficiently modulated by in-plane strains and charge carrier doping. Under a strain range from -5% to 5% and charge carrier doping from -0.3 e to 0.3 e per f.u., the system still retains its FM ordering and the corresponding Tc can be modulated by strains from 233 K to 281 K and by charge carrier doping from 140 K to 245 K. Interestingly, under various strains, the matrix element differences (dz2, dyz), (dx2-y2, dxy) and (px, py) of Gd atoms dominate the MAE behaviors, which originates from the competition between the contributions of the Gd-d orbitals, Gd-p orbitals, and p orbitals of halogen atoms based on the second-order perturbation theory. Inequivalent Dirac valleys are not energetically degenerate due to the time-reversal symmetry breaking in the Janus 2H-GdIBr monolayer. A considerable valley gap between the Berry curvature at the K and K' points provides an opportunity to selectively control the valley freedom and states. External tensile (compressive) strain further increases (decreases) the valley gap up to a maximum (minimum) value of 158 (37) meV, indicating that the valley polarization in the Janus 2H-GdIBr monolayer is robust to external strains. This study provides a novel paradigm and platform to design spintronic devices for next-generation quantum information technology.
Collapse
Affiliation(s)
- Cunquan Li
- Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, Tianjin Key Laboratory for Photoelectric Materials and Devices, National Demonstration Center for Experimental Function Materials Education, School of Material Science and Engineering, Tianjin University of Technology, Tianjin, 300384, China.
| | - Yukai An
- Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, Tianjin Key Laboratory for Photoelectric Materials and Devices, National Demonstration Center for Experimental Function Materials Education, School of Material Science and Engineering, Tianjin University of Technology, Tianjin, 300384, China.
| |
Collapse
|
3
|
Moin M, Anwar AW, Ali A, Nabi S, Bashir MZ, Ali S, Bilal S, Haq NU. A comprehensive correlated analysis of Ra-Doped (ZnO 2, ZnO) for optoelectronic applications: a first-principle study. J Mol Model 2023; 29:44. [PMID: 36653515 DOI: 10.1007/s00894-022-05425-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 12/16/2022] [Indexed: 01/20/2023]
Abstract
CONTEXT Zinc oxide (ZnO) exhibits bulk-like behavior and is modified by radium doping to attain favorable electronic properties. The elastic and mechanical response of ZnO2 is much more favorable than ZnO material. The change in thermal expansion, Debye temperature, free energy, entropy, and specific heat leads it to be a good candidate for thermodynamic applications at low and high temperatures. Optical properties like dielectric function, absorption, refraction, reflection, and refractive index obtained after suitable doping transform the material as optically active. ZnO2 has low reflectivity and zero absorption below the electronic band gap as compared to ZnO in a wider spectral range. Our analyses on doped ZnO2 and ZnO make us confident for a wide range of applications in optoelectronic and anti-bacterial treatment in biomedical devices. Especially due to high flexibility and high light transmission, ZnO2 is an excellent applicant for transparent electrodes. METHODS Density functional theory has been employed in consistency with generalized gradient approximation (GGA) with PBEsol to analyze the structural, electronic, elastic, mechanical, thermodynamic, and optical response of pure and Ra-doped (ZnO2 and ZnO) materials.
Collapse
Affiliation(s)
- Muhammad Moin
- Department of Physics, University of Engineering and Technology, Lahore, 54890, Pakistan
| | - Abdul Waheed Anwar
- Department of Physics, University of Engineering and Technology, Lahore, 54890, Pakistan.
| | - Anwar Ali
- Department of Physics, University of Engineering and Technology, Lahore, 54890, Pakistan
| | - Shafqat Nabi
- Department of Physics, University of Engineering and Technology, Lahore, 54890, Pakistan
| | - M Zeeshan Bashir
- Department of Physics, University of Engineering and Technology, Lahore, 54890, Pakistan
| | - Shahid Ali
- Department of Physics, University of Engineering and Technology, Lahore, 54890, Pakistan
| | - Shahid Bilal
- Department of Physics, University of Engineering and Technology, Lahore, 54890, Pakistan
| | - Najam Ul Haq
- Department of Physics, Comsats University Lahore, Lahore, 54000, Pakistan
| |
Collapse
|
4
|
Ghosh PS, Arya A, Basak CB, Poswal AK, Banerjee S. Chemical ordering as a precursor to formation of ordered δ-UZr 2phase: a theoretical and experimental study. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:254003. [PMID: 33765664 DOI: 10.1088/1361-648x/abf20b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 03/25/2021] [Indexed: 06/12/2023]
Abstract
A combination of special quasi-random structure (SQS) analysis, density functional theory (DFT) based simulations and experimental techniques are employed in determining the transformation pathway for the disorderedγ-(U, Zr) phase (bcc structure) to transform into the chemically orderedδ-UZr2phase (C32, AlB2type structure). A novel Monte-Carlo based strategy is developed to generate SQS structures to study theβ→ωdisplacive phase transformation in A1-xBxbinary random alloy. Structures generated with this strategy and using DFT calculations, it is determined that (222)bccplane collapse mechanism is energetically unfavorable in chemically disordered environment at UZr2composition. A mechanically and dynamically stable 24 atom SQS structure is derived which serves as a structural model of chemically orderedδ-UZr2structure. Finally, a thermodynamic basis for the mechanism of theγtoδtransformation has been established which ensures chemical ordering is a precursor to the subsequent displacive transformation to form chemically orderedδ-UZr2structure.
Collapse
Affiliation(s)
- P S Ghosh
- Glass and Advanced Materials Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - A Arya
- Glass and Advanced Materials Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - C B Basak
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
- Mechanical Metallurgy Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - A K Poswal
- Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - S Banerjee
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| |
Collapse
|
5
|
Assessing Relativistic Effects and Electron Correlation in the Actinide Metals Th to Pu. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9235020] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Density functional theory (DFT) calculations are employed to explore and assess the effects of the relativistic spin–orbit interaction and electron correlations in the actinide elements. Specifically, we address electron correlations in terms of an intra-atomic Coulomb interaction with a Hubbard U parameter (DFT + U). Contrary to recent beliefs, we show that for the ground-state properties of the light actinide elements Th to Pu, the DFT + U makes its best predictions for U = 0. Actually, our modeling suggests that the most popular DFT + U formulation leads to the wrong ground-state phase for plutonium. Instead, extending DFT and the generalized gradient approximation (GGA) with orbital–orbital interaction (orbital polarization; OP) is the most accurate approach. We believe the confusion in the literature on the subject mostly originates from incorrectly accounting for the spin–orbit (SO) interaction for the p1/2 state, which is not treated in any of the widely used pseudopotential plane-wave codes. Here, we show that for the actinides it suffices to simply discard the SO coupling for the p states for excellent accuracy. We thus describe a formalism within the projector-augmented-wave (PAW) scheme that allows for spin–orbit coupling, orbital polarization, and non-collinear magnetism, while retaining an efficient calculation of Hellmann–Feynman forces. We present results of the ground-state phases of all the light actinide metals (Th to Pu). Furthermore, we conclude that the contribution from OP is generally small, but substantial in plutonium.
Collapse
|
6
|
Ground-State and Thermodynamical Properties of Uranium Mononitride from Anharmonic First-Principles Theory. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9183914] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We report on an advanced density-functional theory (DFT) approach for investigating the ground-state and thermodynamical properties of uranium mononitride (UN). The electronic structure for UN at zero temperature is obtained from DFT that utilizes the generalized gradient approximation (GGA) for the electron exchange and correlation functional and includes spin-orbit interaction and an extension with orbital polarization. Thermodynamical properties are computed within the quasi-harmonic approximation in the Debye–Grüneisen model while anharmonicity is captured in the self-consistent ab initio lattice dynamics (SCAILD) scheme. Anharmonic phonons have heretofore never been modeled from first-principles for UN but they turn out to be important. The computed free energy compares well with that of a CALPHAD (CALculation of PHAse Diagrams) assessment of available experimental data.
Collapse
|
7
|
Harrison N, Betts JB, Wartenbe MR, Balakirev FF, Richmond S, Jaime M, Tobash PH. Phase stabilization by electronic entropy in plutonium. Nat Commun 2019; 10:3159. [PMID: 31320635 PMCID: PMC6639308 DOI: 10.1038/s41467-019-11166-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 06/26/2019] [Indexed: 11/29/2022] Open
Abstract
Plutonium metal undergoes an anomalously large 25% collapse in volume from its largest volume δ phase (δ-Pu) to its low temperature α phase, yet the underlying thermodynamic mechanism has largely remained a mystery. Here we use magnetostriction measurements to isolate a previously hidden yet substantial electronic contribution to the entropy of δ-Pu, which we show to be crucial for the stabilization of this phase. The entropy originates from two competing instabilities of the 5f-electron shell, which we show to drive the volume of Pu in opposing directions, depending on the temperature and volume. Using calorimetry measurements, we establish a robust thermodynamic connection between the two excitation energies, the atomic volume, and the previously reported excess entropy of δ-Pu at elevated temperatures. Plutonium has strong electronic correlations, which makes it difficult to establish microscopic understanding of the complicated structural phase diagram. Here the authors identify an electronic contribution to the entropy that stabilises the δ-Pu phase.
Collapse
Affiliation(s)
- N Harrison
- Los Alamos National Laboratory, Los Alamos, Mail Stop E536, Los Alamos, NM, 87545, USA.
| | - J B Betts
- Los Alamos National Laboratory, Los Alamos, Mail Stop E536, Los Alamos, NM, 87545, USA
| | - M R Wartenbe
- Los Alamos National Laboratory, Los Alamos, Mail Stop E536, Los Alamos, NM, 87545, USA
| | - F F Balakirev
- Los Alamos National Laboratory, Los Alamos, Mail Stop E536, Los Alamos, NM, 87545, USA
| | - S Richmond
- Los Alamos National Laboratory, Los Alamos, Mail Stop E574, Los Alamos, NM, 87545, USA
| | - M Jaime
- Los Alamos National Laboratory, Los Alamos, Mail Stop E536, Los Alamos, NM, 87545, USA
| | - P H Tobash
- Los Alamos National Laboratory, Los Alamos, Mail Stop E574, Los Alamos, NM, 87545, USA
| |
Collapse
|
8
|
de Coss-Martínez R, González-Castelazo P, De la Peña-Seaman O, Heid R, Bohnen KP. Effect of doping on lattice dynamics and electron-phonon coupling of the actinides Ac-Th alloy. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:355401. [PMID: 28653960 DOI: 10.1088/1361-648x/aa7c05] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We have studied the electronic, lattice dynamical, and electron-phonon properties of the actinides [Formula: see text]Th x alloy within the framework of density functional perturbation theory. The self-consistent virtual crystal approximation is used for the alloy modeling, and spin-orbit coupling is included in the calculation of all relevant quantities. An overall decrease of the electron-phonon coupling (λ) by [Formula: see text] from Ac to Th was observed. However, its dependence on x shows a non-linear behavior. λ reduces just 6% from Ac to a Th content of [Formula: see text], then drops drastically (∼[Formula: see text]) from there until [Formula: see text]. The large decrease of λ for [Formula: see text] is due to the reduction of the density of states at the Fermi level ([Formula: see text]), combined with a general phonon hardening. On contrast, the behavior for [Formula: see text] is the result of a subtle balance between an enhancement of phase space and the above mentioned effects on [Formula: see text] and the phonons. The phase-space enhancement is related to the appearance of Kohn anomalies, which fade away as the Th concentration increases.
Collapse
Affiliation(s)
- R de Coss-Martínez
- Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apartado Postal J-48 C.P. 72570 Puebla, Puebla, Mexico
| | | | | | | | | |
Collapse
|
9
|
Söderlind P, Zhou F, Landa A, Klepeis JE. Phonon and magnetic structure in δ-plutonium from density-functional theory. Sci Rep 2015; 5:15958. [PMID: 26514238 PMCID: PMC4626764 DOI: 10.1038/srep15958] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 10/05/2015] [Indexed: 11/09/2022] Open
Abstract
We present phonon properties of plutonium metal obtained from a combination of density-functional-theory (DFT) electronic structure and the recently developed compressive sensing lattice dynamics (CSLD). The CSLD model is here trained on DFT total energies of several hundreds of quasi-random atomic configurations for best possible accuracy of the phonon properties. The calculated phonon dispersions compare better with experiment than earlier results obtained from dynamical mean-field theory. The density-functional model of the electronic structure consists of disordered magnetic moments with all relativistic effects and explicit orbital-orbital correlations. The magnetic disorder is approximated in two ways: (i) a special quasi-random structure and (ii) the disordered-local-moment method within the coherent potential approximation. Magnetism in plutonium has been debated intensely, but the present magnetic approach for plutonium is validated by the close agreement between the predicted magnetic form factor and that of recent neutron-scattering experiments.
Collapse
Affiliation(s)
- Per Söderlind
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - F Zhou
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - A Landa
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - J E Klepeis
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| |
Collapse
|
10
|
Site-selective electronic correlation in α-plutonium metal. Nat Commun 2013; 4:2644. [DOI: 10.1038/ncomms3644] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 09/19/2013] [Indexed: 11/08/2022] Open
|
11
|
Obodo KO, Chetty N. First principles LDA + U and GGA + U study of protactinium and protactinium oxides: dependence on the effective U parameter. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:145603. [PMID: 23478314 DOI: 10.1088/0953-8984/25/14/145603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The electronic structure and properties of protactinium and its oxides (PaO and PaO2) have been studied within the framework of the local density approximation (LDA), the Perdew-Burke-Ernzerhof generalized gradient approximation [GGA(PBE)], LDA + U and GGA(PBE) + U implementations of density functional theory. The dependence of selected observables of these materials on the effective U parameter has been investigated in detail. The examined properties include lattice constants, bulk moduli, the effect of charge density distributions, the hybridization of the 5f orbital and the energy of formation for PaO and PaO2. The LDA gives better agreement with experiment for the bulk modulus than the GGA for Pa but the GGA gives better structural properties. We found that PaO is metallic and PaO2 is a Mott-Hubbard insulator. This is consistent with observations for the other actinide oxides. We discover that GGA and LDA incorrectly give metallic behavior for PaO2. The GGA(PBE) + U calculated indirect band gap of 3.48 eV reported for PaO2 is a prediction and should stimulate further studies of this material.
Collapse
Affiliation(s)
- K O Obodo
- Physics Department, University of Pretoria, Pretoria 0002, South Africa.
| | | |
Collapse
|
12
|
Bouchet J, Albers RC. Elastic properties of the light actinides at high pressure. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:215402. [PMID: 21558598 DOI: 10.1088/0953-8984/23/21/215402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Using density-functional perturbation theory, we have calculated the elastic constants for the ground-state crystal structures of the light actinide metals both at their equilibrium volumes (for Th through Np) and as a function of pressure (for Th through U). As necessary, we take into account the effects of atomic relaxation and show that these can be neglected for α-U, but are crucial for α-Np. The elastic constants of Th and U are compared with experimental measurements near ambient conditions and good agreement is found. Studies of the Born stability criteria in pressure reveal that Th and Pa are mechanically unstable while U remains stable up to 85 GPa, as is observed in diamond anvil cell experiments.
Collapse
Affiliation(s)
- J Bouchet
- CEA, DAM, DIF, F-91297 Arpajon, France
| | | |
Collapse
|
13
|
Savrasov SY, Toropova A, Katsnelson MI, Lichtenstein AI, Antropov V, Kotliar G. Electronic structure and magnetic properties of solids. Z KRIST-CRYST MATER 2009. [DOI: 10.1524/zkri.220.5.473.65072] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
We review basic computational techniques for simulations of various magnetic properties of solids. Several applications to compute magnetic anisotropy energy, spin wave spectra, magnetic susceptibilities and temperature dependent magnetisations for a number of real systems are presented for illustrative purposes.
Collapse
|
14
|
Fronzi M, Soon A, Delley B, Traversa E, Stampfl C. Stability and morphology of cerium oxide surfaces in an oxidizing environment: A first-principles investigation. J Chem Phys 2009. [DOI: 10.1063/1.3191784] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
15
|
Affiliation(s)
- T. Petit
- a CEA-Grenoble, Direction des Reacteurs Nucleaires, Départment de Thermohydraulique et de Physique , Service d'Etudes du Comportement des Combustibles , 17 rue des Martyrs, 38054 , Grenoble Cedex 9 , France
| | - B. Morel
- a CEA-Grenoble, Direction des Reacteurs Nucleaires, Départment de Thermohydraulique et de Physique , Service d'Etudes du Comportement des Combustibles , 17 rue des Martyrs, 38054 , Grenoble Cedex 9 , France
- d COMURHEX , BP 29, 26701 , Pierrelatte Cedex , France
| | - C. Lemaignan
- a CEA-Grenoble, Direction des Reacteurs Nucleaires, Départment de Thermohydraulique et de Physique , Service d'Etudes du Comportement des Combustibles , 17 rue des Martyrs, 38054 , Grenoble Cedex 9 , France
| | - A. Pasturel
- b CNRS, Laboratoire d'Experimentation Numérique , Maison des Magistères, BP 166, 38042 , Grenoble Cedex 9 , France
| | - B. Bigot
- c Ecole Normale Superieure de Lyon, Laboratoire de Chimie Théorique , 46 Allee d'ltalie, 69364 , Lyon Cedex 07 , France
| |
Collapse
|
16
|
Trickeya S, Alforda J, Boetggerb J. Methods and Implementation of Robust, High-Precision Gaussian Basis DFT Calculations for Periodic Systems: the GTOFF Code. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/s1380-7323(04)80020-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
|
17
|
Dai X, Savrasov SY, Kotliar G, Migliori A, Ledbetter H, Abrahams E. Calculated phonon spectra of plutonium at high temperatures. Science 2003; 300:953-5. [PMID: 12738856 DOI: 10.1126/science.1083428] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We constructed computer-based simulations of the lattice dynamical properties of plutonium using an electronic structure method, which incorporates correlation effects among the f-shell electrons and calculates phonon spectra at arbitrary wavelengths. Our predicted spectrum for the face-centered cubic delta phase agrees well with experiments in the elastic limit and explains unusually large shear anisotropy of this material. The spectrum of the body-centered cubic phase shows an instability at zero temperature over a broad region of the wave vectors, indicating that this phase is highly anharmonic and can be stabilized at high temperatures by its phonon entropy.
Collapse
Affiliation(s)
- X Dai
- Department of Physics and Astronomy and Center for Materials Theory, Rutgers University, Piscataway, NJ08854, USA
| | | | | | | | | | | |
Collapse
|
18
|
Savrasov SY, Kotliar G, Abrahams E. Correlated electrons in delta-plutonium within a dynamical mean-field picture. Nature 2001; 410:793-5. [PMID: 11298442 DOI: 10.1038/35071035] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Given the practical importance of metallic plutonium, there is considerable interest in understanding its fundamental properties. Plutonium undergoes a 25 per cent increase in volume when transformed from its alpha-phase (which is stable below 400 K) to the delta-phase (stable at around 600 K), an effect that is crucial for issues of long-term storage and disposal. It has long been suspected that this unique property is a consequence of the special location of plutonium in the periodic table, on the border between the light and heavy actinides-here, electron wave-particle duality (or itinerant versus localized behaviour) is important. This situation has resisted previous theoretical treatment. Here we report an electronic structure method, based on dynamical mean-field theory, that enables interpolation between the band-like and atomic-like behaviour of the electron. Our approach enables us to study the phase diagram of plutonium, by providing access to the energetics and one-electron spectra of strongly correlated systems. We explain the origin of the volume expansion between the alpha- and delta-phases, predict the existence of a strong quasiparticle peak near the Fermi level and give a new viewpoint on the physics of plutonium, in which the alpha- and delta-phases are on opposite sides of the interaction-driven localization-delocalization transition.
Collapse
Affiliation(s)
- S Y Savrasov
- Department of Physics and Astronomy and Center for Materials Theory, Rutgers University, Piscataway, New Jersey 08854-8019, USA.
| | | | | |
Collapse
|
19
|
Pickard CJ, Winkler B, Chen RK, Payne MC, Lee MH, Lin JS, White JA, Milman V, Vanderbilt D. Structural properties of lanthanide and actinide compounds within the plane wave pseudopotential approach. PHYSICAL REVIEW LETTERS 2000; 85:5122-5125. [PMID: 11102201 DOI: 10.1103/physrevlett.85.5122] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2000] [Indexed: 05/23/2023]
Abstract
We show that plane wave ultrasoft pseudopotential methods readily extend to the calculation of the structural properties of lanthanide and actinide containing compounds. This is demonstrated through a series of calculations performed on UO, UO2, UO3, U3O8, UC2, alpha-CeC2, CeB6, CeSe, CeO2, NdB6, TmOI, LaBi, LaTiO3, YbO, and elemental Lu.
Collapse
Affiliation(s)
- CJ Pickard
- Institut fur Geowissenschaften, Universitat Kiel, Olshausenstrasse 40 D-24098 Kiel, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Savrasov SY, Kotliar G. Ground state theory of delta-Pu. PHYSICAL REVIEW LETTERS 2000; 84:3670-3673. [PMID: 11019173 DOI: 10.1103/physrevlett.84.3670] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/1999] [Indexed: 05/23/2023]
Abstract
Correlation effects are important for making predictions in the delta phase of Pu. Using a realistic treatment of the intra-atomic Coulomb correlations we address the long-standing problem of computing ground state properties. The equilibrium volume is obtained in good agreement with experiment when taking into account Hubbard U of the order 4 eV. For this U, the calculation predicts a 5f(5) atomiclike configuration with L = 5, S = 5/2, and J = 5/2 and shows a nearly complete compensation between spin and orbital magnetic moments.
Collapse
Affiliation(s)
- SY Savrasov
- Department of Physics and Astronomy and Center for Condensed Matter Theory, Rutgers University, Piscataway, New Jersey 08854-8019, USA
| | | |
Collapse
|
21
|
Boettger J, Trickey S. Inclusion of relativistic effects in Gaussian-basis density functional calculations for extended systems. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s0166-1280(99)00440-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
22
|
Perdew JP, Burke K, Wang Y. Generalized gradient approximation for the exchange-correlation hole of a many-electron system. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:16533-16539. [PMID: 9985776 DOI: 10.1103/physrevb.54.16533] [Citation(s) in RCA: 2972] [Impact Index Per Article: 106.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
23
|
Svane A. Electronic structure of cerium in the self-interaction-corrected local-spin-density approximation. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:4275-4286. [PMID: 9983980 DOI: 10.1103/physrevb.53.4275] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
24
|
Söderlind P, Eriksson O, Johansson B, Wills JM. Theoretical investigation of the high-pressure crystal structures of Ce and Th. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 52:13169-13176. [PMID: 9980505 DOI: 10.1103/physrevb.52.13169] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
25
|
Söderlind P, Johansson B, Eriksson O. Theoretical zero-temperature phase diagram for neptunium metal. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 52:1631-1639. [PMID: 9981225 DOI: 10.1103/physrevb.52.1631] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
26
|
Johansson B, Abrikosov IA, Aldén M, Ruban AV, Skriver HL. Calculated phase diagram for the gamma. PHYSICAL REVIEW LETTERS 1995; 74:2335-2338. [PMID: 10057902 DOI: 10.1103/physrevlett.74.2335] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
27
|
Söderlind P, Eriksson O, Trygg J, Johansson B, Wills JM. Density-functional calculations for cerium metal. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 51:4618-4621. [PMID: 9979309 DOI: 10.1103/physrevb.51.4618] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|