• 제목/요약/키워드: ferrimagnet

검색결과 15건 처리시간 0.025초

New Macroscopic Ferrimagnets in the System Co-TbN

  • Kim, Tae-Wan;Oh, Jung-Keun
    • Journal of Magnetics
    • /
    • 제13권1호
    • /
    • pp.11-18
    • /
    • 2008
  • This study examines a new macroscopic ferrimagnet, Co-TbN. This ferrimagnet, consisting of two metallic phases, Co and TbN, demonstrated the typical macroscopic ferrimagnet properties of a magnetic compensation point and a negative giant magnetoresistance (GMR). The Co-TbN system with 32% TbN composition showed 0.72% GMR in magnetic fields up to 8 kOe at room temperature and 9% GMR in 40 kOe at 250 K. In the Co-TbN system, GMR exhibited a different dependence on temperature from that of ordinary GMR materials whose negative magnetoresistance decreases with increasing temperature. In contrast to ordinary GMR materials whose negative magnetoresistance decreases with increasing temperature, the GMR effect in the Co-TbN system increased with increasing temperature, due to the increase of ferromagnetic alignment of the Co and TbN in the magnetic field caused by the decreased exchange coupling with increasing temperature.

Giant magnetoresistance of new macroscopic ferrimagnets in the system Co-TbN

  • Kim, T. W.;H. B. Chung
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 1998년도 춘계학술대회 논문집
    • /
    • pp.45-48
    • /
    • 1998
  • We first report the GMR effect of new macroscopic ferrimagnet, Co-TbN. The Co-TbN system demonstrates typical macroscopic ferrimagnet properties which are a magnetic compensation Point and negative giant magnetoresistance (GMR) which is caused by the spin scattering contribution quite different from those of ordinary GMR materials. The Co-TbN system with 32 % TbN composition showed 0.72 % GMR in fields up to 8 kOe at room temperature and 9 % GMR at 250 K in 40 kOe. The GMR effect in the Co-TbN system increases with increasing temperature, which is due to the increase of ferromagnetic alignment of the Co and TbN in a field caused by the decrease of exchange coupling by temperature.

  • PDF

The Modified Magnetic Properties of $Mn_3Ga$ Ferrimagnet by Stabilizing on GaSb (001)

  • Feng, Wuwei;Dung, Dang Duc;Cho, Sung-Lae
    • 한국자기학회:학술대회 개요집
    • /
    • 한국자기학회 2009년도 정기총회 및 동계학술연구발표회
    • /
    • pp.203-203
    • /
    • 2009
  • We report on the epitaxial growth of tetragonal $DO_{22}$-type Mn3Ga films on GaSb (001) using molecular beam epitaxy and the related structural and magnetic properties. The as-studied $Mn_3Ga$ film was found to exhibit relatively small coercivity around 400 Oe, which differs greatly from the hard magnetic properties of $Mn_3Ga$ bulk specimen or films that are normally reported. This difference was probably attributed to the effects of the GaSb (001) substrate that forced the $Mn_3Ga$ film to be two-dimensionlly stabilized in the (114) orientation and thus led to the modified intrinsic properties of $Mn_3Ga$ films. The growth orientation of the Mn3Ga (114)//GaSb (001) also caused the easy magnetocrystalline direction located in the film plane due to the dominant shape anisotropy in the thin films.

  • PDF

Exchange Bias in Cr2O3/Fe3O4 Core/Shell Nanoparticles

  • Yun, B.K.;Koo, Y.S.;Jung, J.H.
    • Journal of Magnetics
    • /
    • 제14권4호
    • /
    • pp.147-149
    • /
    • 2009
  • We report the exchange bias in antiferromagnet/ferrimagnet $Cr_2O_3/Fe_3O_4$ core/shell nanoparticles. The magnetic field hysteresis curve for $Cr_2O_3/Fe_3O_4$ nanoparticles after field-cooling (FC) clearly showed both horizontal ($H_{EB}{\sim}$610 Oe) and vertical (${\Delta}M{\sim}$5.6 emu/g) shifts at 5 K. These shifts disappeared as the temperature increased toward the Neel temperature of $Cr_2O_3\;(T_N{\sim}$307 K). The $H_{EB}\;and\;{\Delta}M$ values were sharply decreased between the $1^{st}\;and\;the\;2^{nd}$ magnetic field cycles, and then slowly decreased with further cycling. These results are discussed in terms of the formation of single domains with pinned, uncompensated, antiferromagnetic spin and their evolution into multi-domains with cycling.