• Title/Summary/Keyword: 자기모멘트

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Electronic Structure and Magnetism of Fe Monolayer with Periodic Defects (주기적 결함을 가진 철 단층의 전자구조와 자성)

  • Landge, Kalpana K.;Bialek, Beata;Lee, Jae-Il
    • Journal of the Korean Magnetics Society
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    • v.19 no.5
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    • pp.161-164
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    • 2009
  • The effect of periodic vacancies to the magnetism of the Fe monolayer was investigated by calculating the electronic structures using the full-potential linearized augmented plane wave method within the GGA approximation. We considered four types of vacancies, point defect, I type, + type, and H type which are consisted of one, three, five and seven vacant sites, respectively. We found that the Fe atoms nearest to the vacancy have the largest magnetic moment in each system, and the value of magnetic moment of the atom was increased as the number of vacancy site is increased. The value of the largest magnetic moment in the systems of point defect, I type, + type, and H type are 3.08, 3.09, 3.15, and 3.30 bohr magnetons, respectively.

Electronic and Magnetic Properties of Rare-earth Transition Metal Compound : $LaCo_{13}$ ($LaCo_{13}$ 희토류-전이금속 화합물의 전자기적 물성연구)

  • 민병일;손진군
    • Journal of the Korean Magnetics Society
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    • v.3 no.1
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    • pp.1-6
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    • 1993
  • Electronic and magnetic proper tis of the rare-earth transition metal compound, $LaCo_{13}$, are investigated by performing self-consistent local density functional LMTO (linearized muffin-tin orbital) band structure calculations for both paramagnetic and ferromagnetic phases of $LaCo_{13}$. The calculated magnetic moments for the two types of Co atoms, Co I and Co II, are 1.34 and $1.65{\mu}_{B}$, respectively. The average magnetic moment of Co atoms in the ferromagnetic phase of $LaCo_{13}$ is estimated to be $1.60{\mu}_{B}$, which is in fairly good agreement with the experimental values, $1.56~1.68{\mu}_{B}$.

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A study on the Standing Spin Wave Resonance of Ni-Fe Thin Films. (Ni-Fe 합금박막의 스핀파 공명 연구)

  • 백종성;서영수;김약연;임우영;이수형
    • Journal of the Korean Magnetics Society
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    • v.4 no.2
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    • pp.100-105
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    • 1994
  • Ni-Fe thin films are deposited on the corning glass substrate by means of RF magnetron sputtering system In order to investigate the dependence of the prorerties of Ni-Fe thin films on the film thickness, ferromagnetic reson¬ance spectrum has been examined. The effective magnetization $M_{eff}$ is constant for all samples, while the exchange stiffness constant A increases with the film thickness. A tendency that spectroscopic splitting factor g increases with the sample thickness, we expect that the increase of the contribution of the orbital motion to the magnetic moment as a reason for it.

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Measurement using Low-temperature Scanning Hall Probe Microscopy and Analysis of Local Current Distribution using Inversion Problem Technique (저온 주사 홀소자 현미경과 역변환 방법을 이용한 국소적 전류 분포 분석)

  • Cho, B.R.;Park, S.K.;Park, H.Y.;Ri, H.C.
    • Progress in Superconductivity
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    • v.13 no.1
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    • pp.34-39
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    • 2011
  • We have performed measurements of the local magnetic field distribution of YBCO coated conductors using Low-temperature Scanning Hall Probe Microscopy (LT-SHPM). Distribution of stray magnetic field of various types of YBCO coated conductors in the superconducting state was measured in presence of external magnetic fields. We analyzed one dimensional and two dimensional local current distribution using inversion technique from the magnetic field distribution.

Magnetic Property of ${\mu}$-Peroxo-bis[bis(diphenylglyoximato)iron(Ⅲ)] (${\mu}$-Peroxo-bis[bis(diphenylglyoximato)iron(Ⅲ)]의 자기적 성질)

  • Chong Shik Chin;L. Vaska
    • Journal of the Korean Chemical Society
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    • v.24 no.3
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    • pp.233-238
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    • 1980
  • It was observed that the magnetic moment for iron in $[(DPGH)_2FeO_2Fe(DPGH)_2]$, the oxygenation product of a octahedral iron(Ⅱ) complex, $[Fe(DPGH)_2(NH_3_2]$, decreases with decreasing temperature from ${\mu}$ = 3.60 B.M (Bohr Magneton) per iron at $298^{\circ}$K down to ${\mu}$ = 1.65 B.M per iron at $4.2^{\circ}K$. This observation may be explained by a weak antiferromagnetic coupling between two iron(Ⅲ) atoms of intermediate spin state (S = 3/2) in the molecule with the coupling constant $J = -l cm^{-1}$.

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First-principles Study on the Magnetism of VRu(001) Surface (VRu(001) 표면의 자성에 대한 제일원리 연구)

  • Jang, Y.R.;Song, Ki-Myung;Lee, J.I.
    • Journal of the Korean Magnetics Society
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    • v.17 no.3
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    • pp.109-113
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    • 2007
  • We investigated the magnetic properties of VRu(001) surface by using the all electron full-potenial linearized augmented planewave (FLAPW) energy band method within the GGA. We consider two different configurations, V and Ru surface layers, respectively. The V atoms in surface layer was calculated to have large magnetic moment of $1.71_{{\mu}_B}$ while the Ru surface layer to have nearly nonmagnetic state. The calculated spin-polarized density of states. spin density contour, and charge density were discussed in relation to the magnetic properties of VRu(001) surface.

Magnetocrystalline Anisotropy of α''-Fe16N2 (α''-Fe16N2의 자기결정이방성)

  • Khan, Imran;Son, Jicheol;Hong, Jisang
    • Journal of the Korean Magnetics Society
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    • v.26 no.4
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    • pp.115-118
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    • 2016
  • We investigated the magnetocrystalline anisotropy of pure ${\alpha}^{{\prime}{\prime}}-Fe_{16}N_2$ by using full-potential linearized augmented plane wave method (FLAPW). A very high magnetic moment was obtained for Fe (4d) site due to the lattice expansion in the z-direction, while the magnetic moment of Fe (4e) and (8h) site were suppressed due to hybridization with neighboring N atom. The calculated spin magnetic moments for different Fe sites (4d, 4e and 8h) were in good agreement with previously reported values. Due to the tetragonal distortion, we found a very large uniaxial anisotropy constant of $0.58MJ/m^3$. Besides, a high value of magnetization of 1.76MA/m was obtained. In additon, the estimated coercive field and maximum energy product of 6.51 kOe and 71.7 MGOe were obtained for pure ${\alpha}^{{\prime}{\prime}}-Fe_{16}N_2$. This may suggest that the ${\alpha}^{{\prime}{\prime}}-Fe_{16}N_2$ can be utilized for potential rare-earth free permanent magnet material.

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.

Magnetic Properties of Cr Substituted SiTe Compounds (SiTe에 Cr을 치환한 화합물의 자기적 성질)

  • Landge, Kalpana;Bialek, Beata;Lee, Jae-Il
    • Journal of the Korean Magnetics Society
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    • v.21 no.4
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    • pp.127-131
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    • 2011
  • In this paper, we study the electronic and magnetic properties of Cr substituted SiTe in the rock-salt structure compound using the full potential linearized augmented plane wave method within the generalized gradient approximation to the exchange correlation potential. Two stoichiometries are studied: $CrSi_3Te_4$ with 25 %, and $CrSiTe_2$ with 50 % Cr substitution. We found, from the total energy calculations, that the equilibrium lattice constant for cubic $CrSi_3Te_4$ is 11.64 a.u. and a = 7.89 a.u. and c = 11.13 a.u. for tetragonal $CrSiTe_2$. The integer value of the calculated magnetic moment per unit cell, $4{\mu}_B$ for $CrSiTe_2$ suggests that this compound is halfmetallic. The magnetic moment per unit cell for $CrSi_3Te_4$ is slightly larger than $4{\mu}_B$. The magnetic moment on Cr atoms are 3.61 and $3.62{\mu}_B$ in the $CrSi_3Te_4$ and $CrSiTe_2$, respectively. The presence of Cr atoms causes that the other atoms become slightly magnetized in both compounds. The electronic properties and the magnetism are discussed with the calculated spin-polarized density of states.