• Title/Summary/Keyword: Ferrimagnetic

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Electrically and magnetically Characterization for Ferroelectric/Ferrimagnetic ceramics (PZT/Ferrite 합성 세라믹의 전기적.자기적 특성연구)

  • Kim, Jang-Yong;Oh, Joon-Hak;Moon, Byung-Moo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.30-33
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    • 2001
  • This thesis deal with ferroelectric and ferrimagnetic materials, PZT/Ferrite ceramics. We conducted test of magnetical and electrical measurement. From this measurement, We obtained tunability and we can control characteristic impedance($Z_0$) from permeability($\mu$) and dielectric constant($\varepsilon$) for impedance matching in transmission line.

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Characteristic of Hyperfine Magnesioferrite Particles Possessing Shape Anisotropy

  • Going Yim;Chai Suck Yim
    • The Journal of Engineering Research
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    • v.7 no.1
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    • pp.99-103
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    • 2005
  • The ferrimagnetic resonance technique, with the inclusion of shaper anisotropy effects, was used to obtain information about the early stages in the precipitation of magnesium ferrite from iron-doped magnesia. The very small magnesioferrite particles were produced by precipitation method from solid solution of iron ion in single crystal magnesia. The temperature dependence of the resonance anisotropy field for a coherent assembly of hyperfine magnesium ferrite precipitates was investigated in the range 100~400K. The results are interpreted in terms of the shape anisotropy of the precipitates.

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Electrically and magnetically Characterization for Ferroelectric/Ferrimagnetic ceramics (PZT/Ferrite 합성 세라믹의 전기적.자기적 특성연구)

  • 김장용;오준학;문병무
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.30-33
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    • 2001
  • This thesis deal with ferroelectric and ferrimagnetic materials, PZT/Ferrite ceramics. We conducted test of magnetical and electrical measurement. From this measurement, We obtained tunability and we can control characteristic impedance(Z$_{0}$) from permeability($\mu$) and dielectric constant($\varepsilon$) for impedance matching in transmission line.e.

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XMCD and PES study of a compensated-ferrimagnetic half-metal Mn3Ga

  • Seong, Seungho;Lee, Eunsook;Kim, Hee Yeon;Kim, Younghak;Baik, Jaeyoon;Kang, J.S.
    • Current Applied Physics
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    • v.18 no.11
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    • pp.1190-1195
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    • 2018
  • By employing soft X-ray magnetic circular dichroism (XMCD), soft X-ray absorption spectroscopy (XAS), and photoemission spectroscopy (PES), we have investigated the electronic structure of the candidate zero-moment half-metallic $Mn_3Ga$. We have studied the ball-milled and annealed $Mn_3Ga$ powder samples that exhibit nearly zero magnetization. Mn 2p XAS revealed that Mn ions in $Mn_3Ga$ are nearly divalent for both of the Mn ions having the locally octahedral symmetry and those having the locally tetrahedral symmetry. The measured Mn 2p XMCD spectrum of $Mn_3Ga$ is very similar to that of ferrimagnetic $MnFe_2O_4$ having divalent Mn ions. The sum-rule analysis of the Mn 2p XMCD spectrum shows that both the spin and orbital magnetic moments of Mn ions in $Mn_3Ga$ are negligibly small, in agreement with the nearly compensated-ferrimagnetic ground state of $Mn_3Ga$. The valence-band PES spectrum of $Mn_3Ga$ agrees well with the calculated density of states, supporting the half-metallic electronic structure of $Mn_3Ga$.

Ferrimagnetic Resonance Studies of Poly-crystalline $Mn_x$ Ferrites (Mn-Zn 훼라이트의 자기공명 특성연구)

  • 김정렬;박명희;박윤창
    • Journal of the Korean Magnetics Society
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    • v.2 no.2
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    • pp.105-113
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    • 1992
  • 조성이 Mn$_{x}$Zn$_{1-x}$ Fe$_{2}$O$_{4}$ 훼라이트(x=0.75, 0.52)를 pusher type 연속 전기로를 이용하여 질소 분위기하에서 1360 .deg. C 로 3시간 동안 소결하여 얻어냈다. 본 연구에서는 스피넬 구조인 Mn-Zn 훼라이트의 FMR(Ferrimagnetic Resonance) 스펙트럼 특징과 초기투자율과의 상관성을 조사하고자 EPR X-band 스펙 트로미터를 이용 9.50 GHz의 microwave frequency에서 FMR 실험을 수행하였다. FMR 공명흡수선은 주 자기공명 흡 수선외에 낮은 자기장에서 약한 subsidiary 공명흡수선을 나타내는데 온도변화에 따른 주 자기공명 흡수선과 sub- sidiary 공명흡수선(제2, 제3 공명흡수선)의 세기, 공명선폭, g값 등의 온도 의존성을 연구함으로써 제2 공명흡수 선이 나타나는 원인을 분석하였으며, 자기공명 흡수선의 g값, 자기공명선 세기, 그리고 공명선폭과 초기투자율의 상관성을 연구하였다. 실험 결과 주 자기공명 흡수선의 g값, 자기공명선 세기, 공명선폭은 초기투자율 값과 밀접 한 관련이 있음을 확인할 수 있었다.었다.

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Crystallographic and Magnetic Properties of the Ferrimagnetic $Fe_7Se_8$ by M$\ddot{o}$ssbauer Spectroscopy (뫼스바우어 분광법에 의한 준강자성체 $Fe_7Se_8$의 결정학적 특성 및 자기적 특성)

  • 조용호;김효준;이동욱;김응찬;남효덕
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.1
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    • pp.62-66
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    • 1998
  • M$\ddot{o}$ssbauer spectra of ferrimagnetic $Fe_2SE_8$ prepared with $^{57}Fe$ enriched iron have been taken at 298 K and below 78K, and Fe\ulcornerSe\ulcorner has been studied by X-ray diffraction. The crystal structure is found to be a "3c" hexagonal superstructure of the NiAs structure. Three sets of six-line hyperfine patterns were obtained and assigned to three magnetically nonequivalent sites of a superstructure of the crystal. The iron ions at all three sites are found to be in a highly covalent ferrous state. It is shown that the results obtained at the low temperature region are well consistent with Okazaki's "3c" superstructure model.uperstructure model.

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