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High-Throughput Screening of Rare-Earth-Lean Intermetallic 1-13-X Compounds for Good Hard-Magnetic Properties. METALS 2019. [DOI: 10.3390/met9101096] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
By computational high-throughput screening, the spontaneous magnetization M s , uniaxial magnetocrystalline anisotropy constant K 1 , anisotropy field H a , and maximum energy product ( B H ) max are estimated for ferromagnetic intermetallic phases with a tetragonal 1-13-X structure related to the LaCo 9 Si 4 structure type. For SmFe 13 N, a ( B H ) max as high as that of Nd 2 Fe 14 B and a comparable K 1 are predicted. Further promising candidates of composition SmFe 12 AN with A = Co, Ni, Cu, Zn, Ga, Ti, V, Al, Si, or P are identified which potentially reach (BH) max values higher than 400 kJ/m 3 combined with significant K 1 values, while containing almost 50% less rare-earth atoms than Nd 2 Fe 14 B.
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Abstract
A partial substitution such as Ce in SmCo 5 could be a brilliant way to improve the magnetic performance, because it will introduce strain in the structure and breaks the lattice symmetry in a way that enhances the contribution of the Co atoms to magnetocrystalline anisotropy. However, Ce substitutions, which are benefit to improve the magnetocrystalline anisotropy, are detrimental to enhance the Curie temperature ( T C ). With the requirements of wide operating temperature range of magnetic devices, it is important to quantitatively explore the relationship between the T C and ferromagnetic exchange energy. In this paper we show, based on mean-field approximation, artificial tensile strain in SmCo 5 induced by substitution leads to enhanced effective ferromagnetic exchange energy and T C , even though Ce atom itself reduces T C .
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Massive Stokes shift in 12-coordinate Ce(NO2) 63-: crystal structure, vibrational and electronic spectra. Sci Rep 2018; 8:16557. [PMID: 30409997 PMCID: PMC6224556 DOI: 10.1038/s41598-018-34889-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 10/27/2018] [Indexed: 11/13/2022] Open
Abstract
The Ce3+ ion in Cs2NaCe(NO2)6 (I), which comprises the unusual Th site symmetry of the Ce(NO2)63− ion, demonstrates the largest Ce-O Stokes shift of 8715 cm−1 and the low emission quenching temperature of 53 K. The activation energy for quenching changes with temperature, attributed to relative shifts of the two potential energy curves involved. The splitting of the Ce3+ 5d1 state into two levels separated by 4925 cm−1 is accounted for by a first principles calculation using the crystal structure data of I. The NO2− energy levels and spectra were investigated also in Cs2NaLa(NO2)6 and modelled by hybrid DFT. The vibrational and electronic spectral properties have been thoroughly investigated and rationalized at temperatures down to 10 K. A comparison of Stokes shifts with other Ce-O systems emphasizes the dependence upon the coordination number of Ce3+.
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Bar AK, Kalita P, Singh MK, Rajaraman G, Chandrasekhar V. Low-coordinate mononuclear lanthanide complexes as molecular nanomagnets. Coord Chem Rev 2018. [DOI: 10.1016/j.ccr.2018.03.022] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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5
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Theoretical screening of intermetallic ThMn12-type phases for new hard-magnetic compounds with low rare earth content. Sci Rep 2016; 6:24686. [PMID: 27098547 PMCID: PMC4838828 DOI: 10.1038/srep24686] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 04/01/2016] [Indexed: 11/30/2022] Open
Abstract
We report on theoretical investigations of intermetallic phases derived from the ThMn12-type crystal structure. Our computational high-throughput screening (HTS) approach is extended to an estimation of the anisotropy constant K1, the anisotropy field Ha and the energy product (BH)max. The calculation of K1 is fast since it is based on the crystal field parameters and avoids expensive total-energy calculations with many k-points. Thus the HTS approach allows a very efficient search for hard-magnetic materials for which the magnetization M and the coercive field Hc connected to Ha represent the key quantities. Besides for NdFe12N which has the highest magnetization we report HTS results for several intermetallic phases based on Cerium which are interesting as alternative hard-magnetic phases because Cerium is a less ressource-critical element than Neodymium.
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Miyamachi T, Schuh T, Märkl T, Bresch C, Balashov T, Stöhr A, Karlewski C, André S, Marthaler M, Hoffmann M, Geilhufe M, Ostanin S, Hergert W, Mertig I, Schön G, Ernst A, Wulfhekel W. Stabilizing the magnetic moment of single holmium atoms by symmetry. Nature 2013; 503:242-6. [DOI: 10.1038/nature12759] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 10/09/2013] [Indexed: 11/09/2022]
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Ning L, Zhang L, Hu L, Yang F, Duan C, Zhang Y. DFT calculations of crystal-field parameters for the lanthanide ions in the LaCl3 crystal. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:205502. [PMID: 21540498 DOI: 10.1088/0953-8984/23/20/205502] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We present herein a calculation of crystal-field (CF) parameters for the lanthanide ions in the LaCl(3) crystal, using the density functional theory-based orbital-free embedding formalism in conjunction with the effective Hamiltonian method. The calculated values for the second- and fourth-rank CF parameters agree fairly well with the experimental data. It is found that the effect of ligand polarization plays a crucial role in determining the sign and magnitude of the second-rank CF parameters, while the effect of Pauli repulsion between 4f electrons and the ligands is important for the fourth-rank CF parameters. The usefulness of the present approach is illustrated by a study of the relative preference of Eu(3 + ) occupation on the two distinct Pb(2 + ) sites in the KPb(2)Cl(5) crystal. The computational approach and results discussed in this work are useful for a better understanding and simulation of the CF effect in the lanthanide-containing systems.
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Affiliation(s)
- Lixin Ning
- Department of Physics, Anhui Normal University, Wuhu, Anhui, People's Republic of China.
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Mustafi SM, Mukherjee S, Chary KVR, Cavallaro G. Structural basis for the observed differential magnetic anisotropic tensorial values in calcium binding proteins. Proteins 2006; 65:656-69. [PMID: 16981203 DOI: 10.1002/prot.21121] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Lanthanide ions (Ln(3+)), which have ionic radii similar to those of Ca(2+), can displace the latter in a calcium binding protein, without affecting its tertiary structure. The paramagnetic Ln(3+) possesses large anisotropic magnetic susceptibilities and produce pseudocontact shifts (PCSs), which have r(-3) dependence. The PCS can be seen for spins as far as 45 A from the paramagnetic ion. They aid in structure refinement of proteins by providing long-range distance constraints. Besides, they can be used to determine the interdomain orientation in multidomain proteins. This is particularly important in the context of a calcium binding protein from Entamoeba histolytica (EhCaBP), which consists of two globular domains connected by a flexible linker region containing 8 residues. As a first step to obtain the interdomain orientation in EhCaBP, a suite of 2D and 3D heteronuclear experiments were recorded on EhCaBP by displacing calcium with Ce(3+), Ho(3+), Er(3+), Tm(3+), Dy(3+), and Yb(3+) ions in separate experiments, and the PCS of (1)H(N) and (15)N spins were measured. Such data have been used in the refinement of the individual domain structures of the protein in parallel with the calculation of the respective magnetic anisotropy tensorial values, which differ substantially (2.1-2.8 times) from what is found in other Ca(2+) binding loops. This study provides a structural basis for such variations in the magnetic anisotropy tensorial values.
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Affiliation(s)
- Sourajit M Mustafi
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
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9
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Bowden GJ, de Groot PAJ, Rainford BD, Wang K, Martin KN, Zimmermann JP, Fangohr H. Magnetic anisotropy terms in [110] MBE-grown REFe(2) films involving the strain term ε(xy). JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2006; 18:5861-5871. [PMID: 21690802 DOI: 10.1088/0953-8984/18/26/006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The magnetic anisotropy parameters in [110] MBE-grown films of REFe(2) (RE, rare earth) compounds are not the same as those in the bulk. This is due to the presence of a shear strain ε(xy), frozen-in during crystal growth. In this paper, magnetic anisotropy parameters for [110] MBE-grown REFe(2) films, that directly involve the shear strain ε(xy), are presented and discussed. In addition to the usual first-order Callen and Callen term [Formula: see text], there are nine second-order terms, six of which involve cross-terms between ε(xy) and the cubic crystal field terms B(4) and B(6). Two of the second-order cross-terms are identified as being important: [Formula: see text] and [Formula: see text]. Of these, the rank-two term [Formula: see text] dominates over a large temperature range. It has the same angular dependence as the first-order term [Formula: see text], but with a more rapid temperature dependence. The correction at T = 0 K for TbFe(2), DyFe(2), HoFe(2), ErFe(2) and TmFe(2), amounts to ∼+9.2%, -13.9%, -11.6%, +14.3%, and 27.1%, respectively. Similar comments are made concerning the rank-four [Formula: see text] term.
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Affiliation(s)
- G J Bowden
- School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, UK
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Ren J, Whangbo MH, Dai D, Li L. Description of ligand field splitting in terms of density functional theory: Split levels of the lowest-lying subterms of the 4fn−16s2 (n=3–14) configurations in lanthanide monofluorides LnF (Ln=Pr–Yb). J Chem Phys 1998. [DOI: 10.1063/1.476276] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- J. Ren
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204
| | - M.-H. Whangbo
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204
| | - Dadi Dai
- Department of Chemistry, Peking University, Beijing 100871, People’s Republic of China
| | - Lemin Li
- Department of Chemistry, Peking University, Beijing 100871, People’s Republic of China
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MUROHKA H, YOSHIDA H, UOZUMI Y, NOHTOMI A, SAKAE T, MATOBA M, IWAMOTO O, MAKI T, KOORI N. Application of Tail Subtraction Technique with Particle Identification to a Stacked Spectrometer for Intermediate Energy Protons. J NUCL SCI TECHNOL 1997. [DOI: 10.1080/18811248.1997.9733730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Hiroki MUROHKA
- Department of Nuclear Engineering, Kyushu University , Hakozaki, Higashi-ku, Fukuoka, 812
| | - Hiroki YOSHIDA
- Department of Nuclear Engineering, Kyushu University , Hakozaki, Higashi-ku, Fukuoka, 812
| | - Yusuke UOZUMI
- Department of Nuclear Engineering, Kyushu University , Hakozaki, Higashi-ku, Fukuoka, 812
| | - Akihiro NOHTOMI
- Department of Nuclear Engineering, Kyushu University , Hakozaki, Higashi-ku, Fukuoka, 812
| | - Takeji SAKAE
- Department of Nuclear Engineering, Kyushu University , Hakozaki, Higashi-ku, Fukuoka, 812
| | - Masaru MATOBA
- Department of Nuclear Engineering, Kyushu University , Hakozaki, Higashi-ku, Fukuoka, 812
| | - Osamu IWAMOTO
- Nuclear Data Center, Japan Atomic Energy Research Institute , Tokai-mura, Naka-gun, Ibaraki-ken, 319-11
| | - Takashi MAKI
- School of Health Science, University of Occupational and Environmental Health , Iseigaoka, Yahatanishi-ku, Kitakyushu, 807
| | - Norihiko KOORI
- Faculty of Integrated Arts and Sciences, the University of Tokushima , Minamijyousanjima, Tokushima-shi, 770
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12
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Gignoux D, Schmitt D. Chapter 2 Magnetism of compounds of rare earths with non-magnetic metals. HANDBOOK OF MAGNETIC MATERIALS 1997. [DOI: 10.1016/s1567-2719(97)10006-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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13
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Daalderop GH, Kelly PJ, Schuurmans MF. Magnetocrystalline anisotropy of YCo5 and related RECo5 compounds. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:14415-14433. [PMID: 9983240 DOI: 10.1103/physrevb.53.14415] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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14
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Divis M, Richter M, Eschrig H, Steinbeck L. Ab initio electronic structure, magnetism, and magnetocrystalline anisotropy of UGa2. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:9658-9665. [PMID: 9982522 DOI: 10.1103/physrevb.53.9658] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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15
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Steinbeck L, Richter M, Nitzsche U, Eschrig H. Ab initio calculation of electronic structure, crystal field, and intrinsic magnetic properties of Sm2Fe17, Sm2Fe17N3, Sm2Fe17C3, and Sm2Co17. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:7111-7127. [PMID: 9982157 DOI: 10.1103/physrevb.53.7111] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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16
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Hummler K, Fähnle M. Full-potential linear-muffin-tin-orbital calculations of the magnetic properties of rare-earth-transition-metal intermetallics. I. Description of the formalism and application to the series RCo5 (R=rare-earth atom). PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:3272-3289. [PMID: 9983835 DOI: 10.1103/physrevb.53.3272] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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17
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Kuz'min MD. Single-ion magnetic anisotropy of rare-earth-transition-metal compounds and its description by means of analytical expressions. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 51:8904-8916. [PMID: 9977528 DOI: 10.1103/physrevb.51.8904] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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18
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Oppeneer PM, Hierse W. Two-center overlap integrals over Slater-type orbitals constrained to a spherical integration volume: Analytical expressions. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1994; 50:2232-2238. [PMID: 9911134 DOI: 10.1103/physreva.50.2232] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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19
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Steinbeck L, Richter M, Eschrig H, Nitzsche U. Calculated crystal-field parameters for rare-earth impurities in noble metals. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 49:16289-16292. [PMID: 10010776 DOI: 10.1103/physrevb.49.16289] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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20
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F�hnle M, Hummler K, Liebs M, Beuerle T. Ab initio electron theory for hard-magnetic rare-earth-transition-metal intermetallics. ACTA ACUST UNITED AC 1993. [DOI: 10.1007/bf00331219] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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