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Grasselli F. Investigating finite-size effects in molecular dynamics simulations of ion diffusion, heat transport, and thermal motion in superionic materials. J Chem Phys 2022; 156:134705. [PMID: 35395883 DOI: 10.1063/5.0087382] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The effects of the finite size of the simulation box in equilibrium molecular dynamics simulations are investigated for prototypical superionic conductors of different types, namely, the fluorite-structure materials PbF2, CaF2, and UO2 (type II), and the α phase of AgI (type I). Largely validated empirical force-fields are employed to run ns-long simulations and extract general trends for several properties, at increasing size and in a wide temperature range. This work shows that, for the considered type-II superionic conductors, the diffusivity dramatically depends on the system size and that the superionic regime is shifted to larger temperatures in smaller cells. Furthermore, only simulations of several hundred atoms are able to capture the experimentally observed, characteristic change in the activation energy of the diffusion process, occurring at the order-disorder transition to the superionic regime. Finite-size effects on ion diffusion are instead much weaker in α-AgI. The thermal conductivity is found generally smaller for smaller cells, where the temperature-independent (Allen-Feldman) regime is also reached at significantly lower temperatures. The finite-size effects on the thermal motion of the non-mobile ions composing the solid matrix follow the simple law that holds for solids.
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Affiliation(s)
- Federico Grasselli
- COSMO-Laboratory of Computational Science and Modelling, IMX, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
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2
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López J, Diosa J, García G, Mosquera E, Correa H. Temperature-Dependent Potential for the Molecular Dynamics of the superionic conductor β-PbF2. Heliyon 2022; 8:e09026. [PMID: 35252619 PMCID: PMC8892217 DOI: 10.1016/j.heliyon.2022.e09026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 10/15/2021] [Accepted: 02/24/2022] [Indexed: 11/20/2022] Open
Abstract
Molecular dynamic (MD) calculations were performed to investigate the thermodynamic and structural properties of lead fluoride (PbF2) by using a proposed inter-ionic temperature-dependent potential. This potential allows calculating with high precision the linear thermal expansivity and the lattice parameter as a temperature function. In addition, the potential can be represented as a sum of two contributions, a temperature-independent potential added to another temperature-dependent potential, considered last as a correction justified by the one-dimensional Newtonian quantum equation. Two fitting regions were considered, the first region from 300 to 700 K and the other one from 700 to 900 K. These regions arise naturally due to the smooth and continuous transition that PbF2 undergoes until it reaches the superionic state and, allows us to model with high precision the anomaly in the dependence of the lattice parameter with the temperature of this material, a feature that until now under the molecular dynamic method has not been studied. These results are all in good agreement with the experimental measurements.
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López JD, García G, Correa H, Mosquera E, Diosa JE. Data on A parametric temperature dependent potential for β-PbF 2: A numerical investigation by molecular dynamics. Data Brief 2020; 28:104865. [PMID: 31872003 PMCID: PMC6909252 DOI: 10.1016/j.dib.2019.104865] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 08/28/2019] [Accepted: 11/13/2019] [Indexed: 11/19/2022] Open
Abstract
This article presents the data on a parametric temperature dependent potential for β-PbF2 using molecular dynamics (MD) simulations in the rigid ion approach. The β-PbF2 is an important ionic conductor that exhibit a super ionic behavior at 711 K. The understanding of the temperature effect in its properties is crucial for possible applications in electrode for solid state batteries, Cherenkov detectors, and rare earth host for scintillation screen. The simulations were done in the DL_POLY Classic 1.9 package employing the Buckingham pair-potential type. The data have not been reported nor discussed in the research paper to be submitting.
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Affiliation(s)
- Jeison D. López
- Departamento de Física, Universidad del Valle, A.A. 25360, Cali, Colombia
| | - Griselda García
- Facultad de Física, Pontificia Universidad Católica de Chile, Casille 306, Santiago, Chile
| | - Hernando Correa
- Laboratorio de Optoelectrónica, Universidad del Quindío, A.A 2639, Armenia, Colombia
| | - Edgar Mosquera
- Departamento de Física, Universidad del Valle, A.A. 25360, Cali, Colombia
- Centro de Excelencia en Nuevos Materiales (CENM), Universidad del Valle, A.A. 25360, Cali, Colombia
| | - Jesús E. Diosa
- Departamento de Física, Universidad del Valle, A.A. 25360, Cali, Colombia
- Centro de Excelencia en Nuevos Materiales (CENM), Universidad del Valle, A.A. 25360, Cali, Colombia
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Petrov AV, Salamatov MS, Ivanov-Schitz AK, Murin IV. Nanoscale Effects in PbF2–CdF2 Solid Solutions. CRYSTALLOGR REP+ 2019. [DOI: 10.1134/s106377451905016x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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5
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Cazorla C, Errandonea D. Giant Mechanocaloric Effects in Fluorite-Structured Superionic Materials. NANO LETTERS 2016; 16:3124-3129. [PMID: 27070506 DOI: 10.1021/acs.nanolett.6b00422] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Mechanocaloric materials experience a change in temperature when a mechanical stress is applied on them adiabatically. Thus, far, only ferroelectrics and superelastic metallic alloys have been considered as potential mechanocaloric compounds to be exploited in solid-state cooling applications. Here we show that giant mechanocaloric effects occur in hitherto overlooked fast ion conductors (FIC), a class of multicomponent materials in which above a critical temperature, Ts, a constituent ionic species undergoes a sudden increase in mobility. Using first-principles and molecular dynamics simulations, we found that the superionic transition in fluorite-structured FIC, which is characterized by a large entropy increase of the order of 10(2) JK(-1) kg(-1), can be externally tuned with hydrostatic, biaxial, or uniaxial stresses. In particular, Ts can be reduced several hundreds of degrees through the application of moderate tensile stresses due to the concomitant drop in the formation energy of Frenkel pair defects. We predict that the adiabatic temperature change in CaF2 and PbF2, two archetypal fluorite-structured FIC, close to their critical points are of the order of 10(2) and 10(1) K, respectively. This work advocates that FIC constitute a new family of mechanocaloric materials showing great promise for prospective solid-state refrigeration applications.
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Affiliation(s)
| | - Daniel Errandonea
- Departamento de Física Aplicada (ICMUV), Malta Consolider Team, Universitat de Valencia , 46100 Burjassot, Spain
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Hull S, Norberg ST, Eriksson SG, Mohn CE. Neutron powder diffraction and molecular dynamics study of superionic SrBr2. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:454205. [PMID: 24141005 DOI: 10.1088/0953-8984/25/45/454205] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The nature of the dynamic ionic disorder within the high-temperature superionic phase of strontium bromide, β-SrBr2, has been investigated using reverse Monte Carlo (RMC) modelling of neutron powder diffraction data and complementary ab initio molecular dynamics (MD) simulations. The RMC and MD results are in good agreement and indicate the presence of extensive dynamic disorder within the Br(-) sublattice of the cubic fluorite structure. Rapid anion diffusion predominantly occurs as hops between nearest neighbour sites in the 〈100〉 directions, though the trajectories are markedly curved and pass through the peripheries of the octahedral voids in the cation sublattice. In addition, there are extensive correlations between the motions of individual Br(-), often leading to the formation of a short-lived square antiprism co-ordination environment around the Sr(2+). Such polyhedra are observed within the (ambient temperature) ordered tetragonal crystal structure of α-SrBr2. The nature of the ionic disorder in SrBr2 is of particular interest because it is the only known example of a Br(-)-ion superionic. Owing to the large size of this anion, a comparison with the behaviour of other superionic phases gives an insight into the role of ionic size on the conducting properties within these materials.
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Affiliation(s)
- S Hull
- The ISIS Facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX, UK
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7
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Hull S, Norberg ST, Ahmed I, Eriksson SG, Mohn CE. High temperature crystal structures and superionic properties of SrCl2, SrBr2, BaCl2 and BaBr2. J SOLID STATE CHEM 2011. [DOI: 10.1016/j.jssc.2011.09.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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8
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Picinin A, Silva MAP, Rino JP. The structural inhomogeneity of lead-cadmium fluoride systems and its implications. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:335107. [PMID: 21828601 DOI: 10.1088/0953-8984/21/33/335107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In this paper we present a detailed study of structural and dynamical properties of the CdF(2)-PbF(2) systems. Particular attention is devoted to the processes involving the phase separation, a phenomenon of fundamental importance in the correct description of some dynamical properties, as introduced in our previous works. We show here, that the phase separation trend is observed in the undercooled melt, whether by cooling the liquid below its melting point, or by heating a homogeneous glass at temperatures above T(g). The degree of phase separation depends on the procedure employed to obtain the crystalline materials, and the simplest way to determine this property is by performing an isothermal treatment in the undercooled melt region. The local fluorine environments Q((n)), corresponding to fluorine surrounded by nPb and 4-nCd neighbors, is used as a probe in the average local composition. We demonstrate that the increase in the structural inhomogeneity around the composition with x = 0.35 is the factor which leads to a better fluorine conducting property for the Cd(0.35)Pb(0.65)F(2) solid solution, in addition to providing a correct determination of the melting temperature of the Cd(x)Pb(1-x)F(2) compositions.
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Affiliation(s)
- Adalberto Picinin
- FACIP, Universidade Federal de Uberlândia, Avenida João José Dib, 2545, 38302-000, Ituiutaba, MG, Brazil
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Silva MAP, Dantelle G, Mortier M, Monteil A, Ribeiro SJL, Messaddeq Y, Briois V, Poulain M. Local order around rare earth ions during the devitrification of oxyfluoride glasses. J Chem Phys 2008; 128:244516. [DOI: 10.1063/1.2943672] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Dantelle G, Mortier M, Monteil A, Chaussedent S, Silva MAP. Molecular dynamics simulation study of erbium induced devitrification in vitreous PbF2. J Chem Phys 2007; 127:094509. [PMID: 17824750 DOI: 10.1063/1.2771546] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Molecular dynamics simulations of the devitrification process of a lead fluoride glass doped with Er(3+) ions were carried out. This technique appears to be a relevant way to perform systematic analysis of the system structure and to study the influence of defects on PbF2 crystallization. We modeled the total enthalpy, the radial distribution functions, and the diffracted intensities of systems containing different amounts of Er(3+) ions. We demonstrated by means of different simulations that Er(3+) ions lowered the devitrification temperature of PbF2, in good agreement with the experimental results. The genuine role of Er(3+) ions in the devitrification process of PbF2 has been investigated. Er(3+) ions have an unquestionable influence of the crystallization of PbF2. Although the latter does not start in the nearest neighborhood of Er(3+) ions, the presence of Er(3+) ions in a close environment may favor the lead fluoride crystallization.
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Affiliation(s)
- Géraldine Dantelle
- Laboratoire de Chimie de la Matière Condensée de Paris, ENSCP, UMR 7574, 11 rue Curie, F-75005 Paris, France.
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11
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Ivanov-Shitz AK. Computer simulation of superionic conductors: I. Anionic conductors: Review. CRYSTALLOGR REP+ 2007. [DOI: 10.1134/s1063774507010154] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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12
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Lindan PJD, Gillan MJ. The dynamical simulation of superionic UO2 using shell-model potentials. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/01418639408240127] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- P. J. D. Lindan
- a Department of Physics , Keele University, Keele , Staffordshire , ST5 SBG , England
| | - M. J. Gillan
- a Department of Physics , Keele University, Keele , Staffordshire , ST5 SBG , England
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13
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Silva MAP, Rino JP, Monteil A, Ribeiro SJL, Messaddeq Y. Molecular dynamics simulation on devitrification: isothermal devitrification and thermodynamics of PbF2 glasses. J Chem Phys 2004; 121:7413-20. [PMID: 15473813 DOI: 10.1063/1.1796252] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The vitrification and devitrification features of lead fluoride are investigated by means of molecular dynamic simulations. The influence of heating rate on the devitrification temperature as well as the dependence of the glass properties on its thermal history, i.e., the cooling rate employed, is identified. As expected, different glasses are obtained when the cooling rates differ. Diffusion coefficient analysis during heating of glass and crystal, indicates that the presence of defects on the glassy matrix favors the transition processes from the ionic to a superionic state, with high mobility of fluorine atoms, responsible for the high anionic conduction of lead fluoride. Nonisothermal and isothermal devitrification processes are simulated in glasses obtained at different cooling rates and structural organizations occurring during the heat treatments are clearly observed. When a fast cooling rate is employed during the glass formation, the devitrification of a single crystal (limited by the cell dimensions) is observed, while the glass obtained with slower cooling rate, allowing relaxations and organization of various regions on the glass bulk during the cooling process, devitrifies in more than one crystalline plane.
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Affiliation(s)
- Maurício A P Silva
- Departamento de Física, Universidade Federal de São Carlos, Via Washington Luiz km235, 13565-905 São Carlos, São Paulo, Brazil.
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Silva MAP, Monteil A, Messaddeq Y, Ribeiro SJL. Molecular dynamics simulations on devitrification: The PbF2 case. J Chem Phys 2002. [DOI: 10.1063/1.1501119] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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15
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Hutchings MT, Clausen K, Dickens MH, Hayes W, Kjems JK, Schnabel PG, Smith C. Investigation of thermally induced anion disorder in fluorites using neutron scattering techniques. ACTA ACUST UNITED AC 2000. [DOI: 10.1088/0022-3719/17/22/011] [Citation(s) in RCA: 131] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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18
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Computer simulation of defect motion in model normal and ‘fast ion’ conductors II. SrCl
2. ACTA ACUST UNITED AC 1997. [DOI: 10.1098/rspa.1985.0030] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The molecular dynamics method has been applied to the simulation of the fast-ion conductor SrCl
2
. Calculations have been done at increasing temperatures from low temperatures through the normal and high-conductivity regions into the melt. Because of the periodic boundary conditions imposed and the size of the simulation sample (324 ions), the minimum defect concentration of anion Frenkel defects that can exist in the steady state is 1/216 defects per anion lattice site. At low temperatures Frenkel defects introduced into the initial configuration are eliminated, but at higher temperatures Frenkel defects form spontaneously on the anion sublattice. Anions move primarily in <1 0 0> directions by the vacancy mechanism, although more rarely <1 1 0> jumps also occur. At intermediate temperatures interstitials were observed to make non-collinear interstitialcy jumps, but at higher temperatures the motion of interstitials makes little contribution to mass transport. The vacancies appear to be very mobile and interstitials have little or no chance to move before being annihilated by a wandering vacancy. The picture is thus one of a highly dynamic system in which individual defects do not survive for long. However, it must be recognized that the rigid-ion potential used has its limitations and may overemphasize to some extent the vacancy mobility. There is so much motion on the anion sublattice at temperatures close to melting that various indicators such as the anion–anion radial distribution function, the individual ion displacements in a fixed time, and the anion self-correlation function are quite similar below and above the melting temperature. In this sense therefore, the applied description of sublattice melting does not seem to be inappropriate. However, periodic structure is still recognizable on the anion sublattice until it also disappears on the cation sublattice. The small sample molecular dynamics simulation does not predict defect clustering; this is probably because of limitations of the method and so our results are not necessarily in conflict with recent quasi-elastic neutron scattering results.
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Benenson RE, Roth WL, Gibson WM, Daudin B, Dubus M, Jones CC, Guggenheim HJ. Investigation of the phase transition in lead fluoride by proton channeling. PHYSICAL REVIEW. B, CONDENSED MATTER 1991; 44:6663-6672. [PMID: 9998539 DOI: 10.1103/physrevb.44.6663] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Tachibana F, Kobayashi M, Okazaki H. Residence time and density distribution of silver ions in alpha -Ag2Te by molecular-dynamics simulation. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 40:3360-3363. [PMID: 9992281 DOI: 10.1103/physrevb.40.3360] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Brass A. Molecular dynamics study of the defect behaviour in fluorite structure crystals close to the superionic transition. ACTA ACUST UNITED AC 1989. [DOI: 10.1080/01418618908209823] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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22
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Kapusta B, Guillope M. High ionic diffusivity in the perovskite MgSiO3: A molecular-dynamics study. ACTA ACUST UNITED AC 1988. [DOI: 10.1080/01418618808209955] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Kobayashi M, Ishikawa K, Tachibana F, Okazaki H. Diffusion path and Haven's ratio of mobile ions in alpha -Ag2Te. PHYSICAL REVIEW. B, CONDENSED MATTER 1988; 38:3050-3055. [PMID: 9946644 DOI: 10.1103/physrevb.38.3050] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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