• Title/Summary/Keyword: Surface magnetism

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자성 유체 역학에 의한 광자기-굴절률 통합시도

  • Kim, Myeong-Jun
    • Proceedings of the Optical Society of Korea Conference
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    • 2008.07a
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    • pp.215-216
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    • 2008
  • Electricity unified field is described based on magnetic theory. Maxwell Einstein Lorentz Equation & pair particle photon model was introduced for Photonics. Refractive index is calculated as deceleration and deflection of photon due to photo-induced surface magnetism. MEL equation was proved with magneto-jet assumption.

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First-principles Study on the Half-metallicity and Magnetism of the (001) Surfaces of (AlP)1/(CrP)1 Superlattice ((AlP)1/(CrP)1 초격자계에서 (001) 표면의 자성과 반쪽금속성에 대한 제일원리 연구)

  • Bialek, Beata;Lee, Jae Il
    • Journal of the Korean Magnetics Society
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    • v.25 no.6
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    • pp.175-179
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    • 2015
  • The half-metallicity and magnetism of the (001) surfaces of $(AlP)_1/(CrP)_1$ superlattice were investigated by means of FLAPW (Full-potential Liniarized Augmented Plane Wave) method. We considered four types of (001) surface termination, i.e., Al(S)-, Cr(S)-, P(S)Al(S-1)- and P(S)Cr(S-1)-term systems. We found that only Cr(S)-term system maintains the half-metallicity at the surface as only this system has the calculated magnetic moment of integer number of bohr magnetons. The magnetic moment of Cr(S) atom in the system was $3.02{\mu}_B$ which was increased from the bulk value by the effects of band narrowing and increased spin-splitting at the surface. The electronic density of states of the P(S) atom in the P(S)Al(S-1)-term showed very sharp surface states due to the broken $p_z$ bonds at the surface. We found there is still a strong p-d hybridization between the P(S) and Cr(S-1) layers in the P(S)Cr(S-1)-term which causes a considerable increase of magnetic moment of P(S) atom.

The Half-metallic Properties of (001) and (110) Surfaces of CsSe from the First-principles

  • Bialek, Beata;Lee, Jae Il
    • Journal of Magnetics
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    • v.21 no.1
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    • pp.1-5
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    • 2016
  • We investigated the half-metallicity and magnetism at the (001) and (110) surfaces of CsSe in cesium chloride and zinc-blende structures by using the all-electron full-potential linearized augmented plane wave method within the generalized gradient approximation. From the calculated local density of states, we found that all the surfaces preserve the half-metallicity of the bulk structures. The surfaces with a greater polarity have stronger ferromagnetic properties when terminated with Se atoms; the non-polar surfaces do not change their electronic or magnetic properties considerably as compared with the bulk structures.

A First-principles Calculation of Surface Magnetism of Half-monolayer Ru on Pd(001)

  • Kim, Dong-Chul;Lee, J.I;Jang, Y.R
    • Journal of Magnetics
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    • v.4 no.4
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    • pp.107-110
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    • 1999
  • In order to investigate the magnetism of Ru submonolayer on Pb(001), we have performed first-principles calculations for half-layer of Ru on Pd(001) using the full-potential linearzed augmented plane wave (FLAPW) method. We have found that the magnetic moment of Ru for 0.5 layer is 2.21 B. It is found that substrate Pd layers are polarized by the 0.5 Ru overlayer to have significant magnetic moments. Our results are compared with those obtained by the anomalous Hall effect. The calculated electronic structures, i,e., the spin densities and density of states are presented and discussed in relation with magnetic properties.

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Half-metallicity and Magnetism at the (001) Surfaces of the Quaternary Heusler Alloys CoFeCrZ (Z = Ga, Ge): A First-principles Study (4원 호이슬러 합금 CoFeCrZ(Z = Ga, Ge)의 (001) 표면에서의 자성과 반쪽금속성: 제일원리 계산 연구)

  • Kim, Dong-Chul;Lee, Jae Il
    • Journal of the Korean Magnetics Society
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    • v.25 no.2
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    • pp.31-38
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    • 2015
  • Recently, a first-principles study led to a prediction that quaternary Heusler compounds, CoFeCrZ (Z = Ga, Ge) are excellent half-metallic ferromagnets. In this study, we investigate the electronic and the magnetic properties at the (001) surfaces of CoFeCrGa and CoFeCrGe by means of the full-potential linearized augmented plane wave (FLAPW) method within generalized gradient approximation. We considered two types of surface termination: CoFe-terminated and CrZ-terminated surfaces, Z being either Ga or Ge. From the calculated total magnetic moments and the local density of states, we found that half-metallicity is not preserved for all the surfaces. But the calculated atomic density of states showed that CrGa-terminated surface of the CoFeCrGa is almost half-metallic. The magnetic moment of the Co, Fe, or Cr atoms at the surface or subsurface layers in each system had very different values.

Half-metallic and Magnetic Properties of (001) Surfaces of KCaN2 Compound in full-Heusler Structure

  • Bialek, Beata;Lee, Jae Il
    • Journal of Magnetics
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    • v.18 no.4
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    • pp.375-379
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    • 2013
  • The electronic and the magnetic properties of (001) surface of $KCaN_2$ half-metallic compound with full-Heusler structure are studied with the use of a full-potential linearized augmented plane wave method. Two possible terminations of the surface are considered and only the one with N atoms in the topmost layer is found to retain the half-metallic properties of the bulk. The magnetic properties of N-terminated surface are enhanced compared with the properties of the bulk. The calculated magnetic moments on the N atoms in the $KCaN_2$ are 1.26 ${\mu}_B$ in the bulk and 1.90 ${\mu}_B$ at the surface. The subsurface metal atoms are also slightly polarized. In the surface terminated with metal atoms, not only the half-metallicity is destroyed, but also the magnetic properties of the system are weakened.

Interface dependent magnetic anisotropy of Fe/BaTiO3(001): an ab initio study

  • Choe, Hui-Chae;Jeong, Yong-Jae
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.314-314
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    • 2011
  • Using first principles calculations, we investigated the interface structure effects on the magnetic properties of the Fe/BaTiO3 system. On the BaO-terminated surface, a Fe monolayer is formed as two Fe atoms are adsorbed on the top sites of Ba and O in the ($1{\times}1$) surface unit and a Fe ML is formed on the TiO2-terminated surface as two Fe atoms are adsorbed on the two O top sites. The magnetic anisotropy energy of Fe was higher on the TiO2?-erminated surface (1.5 eV) than on the BaO-terminated surface (0.5 eV). The decomposed electron density of the states showed that the stronger hybridization of Fe with the TiO2 layer than with the BaO layer is the most important reason for the higher magnetic anisotropy energy.

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First-principles Study on Half-metallicity and Magnetism for Zinc-blende CrS(001) Surface (Zinc-blende 구조를 가진 CrS(001) 표면에서의 반쪽금속성과 자성에 대한 제일원리 연구)

  • Byun, Y.S.;Lee, J.I.
    • Journal of the Korean Magnetics Society
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    • v.15 no.5
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    • pp.257-260
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    • 2005
  • We investigated the half-metallicity and magnetism for the zinc-blende CrS(001) surfaces by use of the full-potential linearized augmented plane wave (FLAPW) method. We considered two-types of (001) surfaces terminated by Cr (Cr-Term) and S (S-Term) atoms, respectively. From the calculated layer-by-layer density of states, it is found that both of the systems retain the half-metallicity at the (001) surfaces. The calculated magnetic moment ($4.07\;{\mu}_B$) for the CrS(S) atom in Cr-Term is enhanced considerably compared to the bulk value ($3.61\;{\mu}_B$) while that ($3.15\;{\mu}_B$) of the Cr(S-1) in S-Term is much reduced.

First-principles Study on Magnetism and Electronic Structure of Fe Chain on Ag(001) (Ag(001) 표면 위에 놓인 Fe 선의 자성과 전자구조)

  • Jin, Y.J.;Lee, J.I.
    • Journal of the Korean Magnetics Society
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    • v.15 no.4
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    • pp.217-220
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    • 2005
  • The electronic structure and magnetism of Fe chain along the [110] direction on Ag(001) were investigated by using the all-electron full-potential linearized augmented plane wave (FLAPW) method within generalized gradient approximation (GGA). The magnetic moment of Fe atom in Fe chain is calculated to be $3.02\;{\mu}_B$, which is slightly larger than that ($2.99\;{\mu}_B$) of the Fe[110] chain on Cu(001). The reduced coordination number for the Fe chain induced the Fe-d band narrowing and exchange-splitting enhancement, which are responsible for the large magnetic moment of the Fe chain. The calculated band width of the Fe-d band and the exchange-splitting are 1.7 eV and 3.2 eV, respectively.