• 제목/요약/키워드: Polycrystalline $SmBa_2Cu_3O_y$

검색결과 4건 처리시간 0.016초

다결정 초전도체 ${SmBa_2}{Cu_3}{O_x}$의 자기 이력곡선 (Magnetic hysteresis loops of the polycrystalline superconductor ${SmBa_2}{Cu_3}{O_x}$)

  • 이준호;정미숙;이부영;김건철;김영철;정대영
    • Progress in Superconductivity
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    • 제6권1호
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    • pp.84-88
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    • 2004
  • The polycrystalline superconductor $SmBa_2$$Cu_3$$O_{x}$ is fabricated, and intergranular magnetic properties are investigated using the critical state model, from which some useful parameters such as the critical current density and the intergranular volume fraction are obtained. The curve fitting for M-H hysteresis loop shows that the intergranular critical current density of $SmBa_2$$Cu_3$$O_{x}$ / decreases in the form of ($1-T/T_{c}$ )$^{1.5}$ . The intergranular volume fraction is influenced by granular morphology. From SEM image, the grains of $SmBa_2$$Cu_3$$O_{x}$ are found to be randomly shaped. This mean:; that the intergranular volume fraction of $SmBa_2$$Cu_3$$O_{x}$ / should be smaller than those of superconductors, of which grains are plate-shaped such as Tl-based superconductor.

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Rod-type 종자결정성장법을 이용한 (Sm/Y)-Ba-Cu-O계 초전도체의 미세구조 및 초전도특성 (Microstructure and Superconducting Properties of (Sm/Y)-Ba-Cu-O Superconductor by Rod-type Seed Melt Growth)

  • 김소정
    • 한국전기전자재료학회논문지
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    • 제16권4호
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    • pp.336-342
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    • 2003
  • (Sm/Y)$_{1.8}$B $a_{2.4}$C $u_{3.4}$$O_{7-x}$ [(Sm/Y)1.8] high $T_{c}$ superconductors were directionally grown by Rod-type Seed Melt Growth(RSMG) process in air atmosphere. The sintered polycrystalline N $d_{1.8}$B $a_{2.4}$C $u_{3.4}$$O_{7-x}$(Nd1.8) of rod-type seed crystal grown by extrusion mold process were used for achieving the ab-plane alignment haying large grains perpendicular to the center of (Sm/Y)1.8 samples. The observations using TEM micrographs of the melt-textured (Sm/Y)1.8 samples revealed that the nonsuperconducting (Sm/Y)211 inclusions are uniformly distributed in the superconducting (Sm/Y)123 matrix. The microstructure and superconducting properties were investigated by XRD, TEM and SQUID magnetometer. The RSMG (Sm/Y)1.8 samples showed an onset $T_{c}$ $\geq$ 90 K and sharp superconducting transition.nsition.ion.nsition.