<i>Ab initio</i>ground state and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>L</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn><mml:mo>,</mml:mo><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>x-ray magnetic circular dichroism of Mn-based Heusler alloys

Galanakis, I.; Ostanin, S.; Alouani, M.; Dreyssé, H.; Wills, J. M.

doi:10.1103/physrevb.61.4093

Cited by 97 publications

(45 citation statements)

References 41 publications

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“…32 By contrast, the shoulder on the low energy side of the L 3 white line observed in Mn 2 VAl (Figure 4d) is reproduced in the calculations when the jj coupling term is increased, indicating it originates from stronger crystal field splitting. Additionally, the splitting between the L 3 and L 2 edges is reduced in the case of jj coupling ( Figure 4b); experimentally a reduction in this splitting is also observed for Mn 2 VAl and NiMnSb ( Figure 3) and was previously reported for NiMnSb 35 , further indicating a stronger jj coupling in these materials.…”

Section: Xas and Xmcd At Mn L 32 Edgessupporting

confidence: 79%

Evidence for localized moment picture in Mn-based Heusler compounds

Karel

Bernardi

Wang

et al. 2015

Phys. Chem. Chem. Phys.

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X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) were used to probe the oxidation state and element specific magnetic moments of Mn in Heusler compounds with different crystallographic structure.The results were compared with theoretical calculations, and it was found that in full Heusler alloys, Mn is metallic (oxidation state near 0) on both sublattices. The magnetic moment is large and localized when octahedrally coordinated by the main group element, consistent with previous theoretical work, and reduced when the main group coordination is tetrahedral. By contrast, in the half Heusler compounds the magnetic moment of the Mn atoms is large and the oxidation state is +1 or +2. The magnetic and electronic properties of Mn in full and half Heusler compounds are strongly dependent on the structure and sublattice, a fact that can be exploited to design new materials.

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Section: Xas and Xmcd At Mn L 32 Edgessupporting

confidence: 79%

Evidence for localized moment picture in Mn-based Heusler compounds

Karel

Bernardi

Wang

et al. 2015

Phys. Chem. Chem. Phys.

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“…26 Finally we should note that several other aspects of NiMnSb have been studied using first-principles calculations like the exchange constants and Curie temperatures, 27,28,29 the quasiparticle states 30 and the dynamical effects, 31 the defects and doping, 32,33,34 the structural stability, 35,36 the effect of spin-orbit coupling, 37 the fit of model Hamiltonians to describe NiMnSb, 38,39 orbital magnetism, 40 the pressure and thermal expansion effects, 41 the temperature effect 42 and the magneto-optical properties. 43,44 The half-metallic character of NiMnSb in single crystals has been well-established experimentally. Infrared absorption 45 and spin-polarized positronannihilation 46,47 gave a spin-polarization of ∼100% at the Fermi level.…”

Section: Introductionmentioning

confidence: 99%

Ab initio electronic and magnetic properties of half-metallic NiCrSi and NiMnSi Heusler alloys: The role of defects and interfaces

Galanakis

Özdoğan

Şaşıoğlu

2008

Journal of Applied Physics

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Using state-of-the-art first-principles calculations we study the properties of the ferromagnetic Heusler compounds NiYSi where Y stands for V, Cr or Mn. NiCrSi and NiMnSi contrary to NiVSi are half-metallic at their equilibrium lattice constant exhibiting integer values of the total spin magnetic moment and thus we concentrate on these two alloys. The minority-spin gap has the same characteristics as for the well-known NiMnSb alloy being around ∼1 eV. Upon tetragonalization the gap is present in the density of states even for expansion or contraction of the out-of-plane lattice parameter by 5%. The Cr-Cr and Mn-Mn interactions make ferromagnetism extremely stable and the Curie temperature exceeds 1000 K for NiMnSi. Surface and interfaces with GaP, ZnS and Si semiconductors are not half-metallic but in the case of NiCrSi the Ni-based contacts present spinpolarization at the Fermi level over 90%. Finally, we show that there are two cases of defects and atomic-swaps. The first-ones which involve the Cr(Mn) and Si atoms induce states at the edges of the gap which persists for a moderate-concentration of defects. Defects involving Ni atoms induce states localized within the gap completely destroying the half-metallicity. Based on single-impurity calculations we associate these states to the symmetry of the crystal.

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“…In 1983 de Groot and his collaborators [7] showed that one of them, NiMnSb, has a gap at E F in the minority band. Also PtMnSb [8,9] and CoMnSb [10] have been predicted to be half-ferromagnets. Infrared absorption [11] and spinpolarized positron-annihilation [12] experiments have verified the half-ferromagnetic character of bulk NiMnSb.…”

Section: Introductionmentioning

confidence: 99%

Surface properties of the half-and full-Heusler alloys

Galanakis

2002

J. Phys.: Condens. Matter

227

166

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Abstract. Using a full-potential ab-initio technique I study the electronic and magnetic properties of the (001) surfaces of the half-Heusler alloys, NiMnSb, CoMnSb and PtMnSb and of the full-Heusler alloys Co 2 MnGe, Co 2 MnSi and Co 2 CrAl. The MnSb terminated surfaces of the half-Heusler compounds present properties similar to the bulk compounds and, although the half-metallicity is lost, an important spinpolarisation at the Fermi level. In contrast to this the Ni terminated surface shows an almost zero net spin-polarisation. While the bulk Co 2 MnGe and Co 2 MnSi are almost half-ferromagnetic, their surfaces lose the half-metallic character and the net spin-polarisation at the Fermi level is close to zero. Contrary to these compounds the CrAl terminated (001) surface of Co 2 CrAl shows a spin polarisation of about 84%.

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Ab initioground state andL2,3x-ray magnetic circular dichroism of Mn-based Heusler alloys

Cited by 97 publications

References 41 publications

Evidence for localized moment picture in Mn-based Heusler compounds

Evidence for localized moment picture in Mn-based Heusler compounds

Ab initio electronic and magnetic properties of half-metallic NiCrSi and NiMnSi Heusler alloys: The role of defects and interfaces

Surface properties of the half-and full-Heusler alloys

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