Full-Potential Screened KKR Calculations for Magnetism of Co&lt;SUB&gt;2&lt;/SUB&gt;MnSi, Ni&lt;SUB&gt;2&lt;/SUB&gt;MnAl and Ru&lt;SUB&gt;2&lt;/SUB&gt;MnSi, Based on the Generalized Gradient Approximation

Asato, M.; Ohkubo, M.; Hoshino, T.; Nakamura, F.; Fujima, Nobuhisa; Tatsuoka, Hirokazu

doi:10.2320/matertrans.mra2008100

Cited by 15 publications

(15 citation statements)

References 29 publications

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“…These results may be understood easily by considering that, for the impurity systems of the half-filled d bands, the antiferromagnetism is stable compared with the ferromagnetism, as shown for 3d impurities in Co, Ni and Cu. 12,25,26) We also found that there are two solutions for Z = 25.06125.110. The magnetic moments of two solutions (AF and F) and the energy differences for Z = 25.06125.07 are shown in Fig.…”

Section: Magnetism Of 3d Impurities In Fementioning

confidence: 70%

Full-Potential KKR Calculations for Point Defect Energies in Fe-Based Dilute Alloys, Based on the Generalized-Gradient Approximation

et al. 2013

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We present systematically ab-initio calculations for defect energies of 3d and 4sp impurities (ScGe) in Fe. The calculations are based on the Generalized-Gradient-Approximation in the density-functional formalism and the full-potential Korringa-Kohn-Rostoker (FPKKR) Green's function method. First we examine the distance dependence, from the 1st-to the 10th-neighbors, of the impurity-impurity (II; I = ScGe) interaction energies (E int ) and show that for most cases, the 1st-neighboring II interaction energies (E 1 int ) are dominant. We found that fundamental features of phase diagrams of Fe-based binary alloys, such as segregation, solid solution and order, known experimentally, may be classified by use of the sign and magnitude of E 1 int . Second we discuss the calculated results for the 1st-and 2nd-neighboring interaction energies of 3d and 4sp impurities with perturbed-angular-correlation (PAC)-probe Sn in Fe. The comparison of the calculated results with available experimental results shows that the observed attraction for SnCo, SnNi and SnCu may be understood by the 1st-neighboring interaction energies of these impurity pairs, while the obsreved repulsion for SnGa, and SnGe by the 2nd-neighboring interaction energies of these impurity pairs. We also discuss the magnetism of single impurities X (= ScCu) in Fe. The anti-parallel coupling to the bulk magnetization of the neighboring Fe atoms is stable for ScMn, while the parallel coupling for FeCu.

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Section: Magnetism Of 3d Impurities In Fementioning

confidence: 70%

Full-Potential KKR Calculations for Point Defect Energies in Fe-Based Dilute Alloys, Based on the Generalized-Gradient Approximation

et al. 2013

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“…We have already reproduced the experimental results of these alloys without defects, such as the equilibrium lattice parameters, the ground states of magnetism (FM or anti-FM(AFM)), and the total magnetic moments, and discussed successfully the change of magnetism of Ni 2 MnAl (from FM to AFM) [5], which occurs at elevated temperatures.…”

Section: Introductionmentioning

confidence: 68%

“…The accuracy of the present band calculations for the ideal crystals is discussed in Refs. [5,[13][14][15]. Fig.…”

Section: Methods Of Ab-initio Calculationsmentioning

confidence: 91%

“…Especially, Co-based alloys, such as Co 2 MnSi and Co 2 CrAl, were expected as half-metallic(100% spin polarization at the Fermi level) FM alloys with high Curie temperatures. According to the band calculations, the ground states of Co 2 MnSi and Co 2 CrAl are half-metallic [3][4][5]. However, the measured spin-polarization have been usually less than ∼60% [6] and the measured total magnetic moment of Co 2 CrAl is fairy small (1.55 B ) [7], compared with the band calculation result (3.00 B ) [4].…”

Section: Introductionmentioning

confidence: 91%

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Ab-initio calculations for defect energies in Co2MnSi and Co2CrAl

Hoshino¹,

Fujima²,

Asato³

et al. 2010

Journal of Alloys and Compounds

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a b s t r a c tThe ab-initio band calculations predict that the full-Heusler ferromagnetic alloys at L2 1 structure, such as Co 2 MnSi and Co 2 CrAl, are half-metallic. However, the measured spin polarizations have been usually less than ∼60%. The decrease may be attributed to defects of swaps and antisites. We give ab-initio calculations for the formation energies of isolated swaps in Co 2 MnSi and Co 2 CrAl and isolated antisites in Co 2 MnSi, which may be the important factor to determine the defect concentrations. The present calculations predict that two kinds of antisites (Si in Mn-site and Mn in Co-site) in Co 2 MnSi and one kind of swap (Cr-Al) in Co 2 CrAl, are very likely to be formed because of the small defect energies. Using the calculated results, we clarify the fundamental features of Co 2 MnSi and Co 2 CrAl with defects and discuss how to understand the discrepancies between the band calculation and experimental results.

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“…For examples, Co 2 MnSi is expected as a half-metallic (100% spin-polarization at the Fermi level) FM alloy with high Curie temperature, while Ni 2 MnAl as a FM shape memory alloy. According to the band calculations, both the ground states of Co 2 MnSi and Ni 2 MnAl are FM and Co 2 MnSi is half-metallic [4][5][6]. However, the experimental results are different from the band calculation results: the spin-polarization of only 50-60% for Co 2 MnSi and the anti-FM state for Ni 2 MnAl at elevated temperatures [3,[7][8][9].…”

Section: Introductionmentioning

confidence: 71%

Ab initio study for magnetism in Ni2MnAl full-Heusler alloy: A cluster expansion approach for total energy

Hoshino

Fujima

Asato

2010

Journal of Alloys and Compounds

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a b s t r a c tWe show the accuracy and convergence of our ab initio real-space cluster expansion (CE) approach for total energies of alloys, which is useful for the study of atomic structures and magnetism of A-rich AXY full-Heusler alloys such as Ni 2 MnAl. In the present CE, each and every term is uniquely determined by the combination of total energies of X and Y impurities in A metal with a total energy of A metal (per atom), all of which are accurately calculated by the full-potential KKR program combined with the generalized gradient approximation in the density functional formalism. We show that the magnetic energy of Ni 2 MnAl is reproduced very well by the present CE, from a dilute limit, including up to the 4-body interaction energies of Mn and Al impurities in Ni-bcc metal.

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Full-Potential Screened KKR Calculations for Magnetism of Co<SUB>2</SUB>MnSi, Ni<SUB>2</SUB>MnAl and Ru<SUB>2</SUB>MnSi, Based on the Generalized Gradient Approximation

Cited by 15 publications

References 29 publications

Full-Potential KKR Calculations for Point Defect Energies in Fe-Based Dilute Alloys, Based on the Generalized-Gradient Approximation

Full-Potential KKR Calculations for Point Defect Energies in Fe-Based Dilute Alloys, Based on the Generalized-Gradient Approximation

Ab-initio calculations for defect energies in Co2MnSi and Co2CrAl

Ab initio study for magnetism in Ni2MnAl full-Heusler alloy: A cluster expansion approach for total energy

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