• Title/Summary/Keyword: Superconducting Oxides

Search Result 27, Processing Time 0.039 seconds

Characterization and Electrical Properties in (YNS)BCO Oxides by Rod-type Seeded Melt Growth Process

  • Kim, So-Jung;Park, Jong-Kuk;Lee, Sang-Gyo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2007.06a
    • /
    • pp.243-243
    • /
    • 2007
  • We have studied the electrical properties and microstructure of $(Y_{0.5}Nd_{0.25}Sm_{0.25})Ba_2Cu_3O_y[(YNS)-123]$ Oxides by rod-type seeded melt growth process(RSMG) in air atmosphere. Rod-type $NdBa_2Cu_3O_y${Nd-123) seed crystals made a extrusion process method, were used for achieving the ab-plane alignment having large grains perpendicular to the center of (YNS)-123 samples. The observations using SEM and TEM micrographs of the melt-textured (YNS)-123 samples revealed that the nonsuperconducting $(Y_{0.5}Nd_{0.25}Sm_{0.25})Ba_2Cu_3O_y[(YNS)-211]$ inclusions are uniformly distributed in the superconducting matrix. The microstructure and electrical properties were investigated by XRD, SEM, TEM and DC SQUID magnetometer. The sample showed a sharp superconducting transition at 90 K. The magnetization values of the (YNS)-123 sample exhibited the enhanced electrical properties, compared with $YBa_2Cu_3O_y$(Y-123) sample.

  • PDF

Superconducting Properties of (Sm/Y)-Ba-Cu-0 High Tc Composite Superconductors with CeO2 Additive by Zone-Melt Textured Growth (국부용융성장법으로 제조한 (Sm/Y)-Ba-Cu-0계 고온복합초전도체의 CeO2첨가에 따른 초전도특성)

  • 김소정
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.15 no.3
    • /
    • pp.269-274
    • /
    • 2002
  • (Sm/Y)-Ba-Cu-O system high Tc composite superconductors with/without $CeO_2$ additive were directionally grown by zone-melting process, haying large temperature gradient, In air atmosphere. Cylindrical green rods of $({Sm/y})_{1.8}Ba_{2.4}Cu_{3.4}O_x$ [(Sm/Y)1.8] composite oxides by cold isostatic pressing(CIP) method using rubber mold were fabricated. The microstructure and superconducting properties were investigated by XRD, SEM, TEM and SQUID magnetometer. The size of nonsuperconducting $({Sm/y})_2BaCuO_5$ inclusions of the melt-textured (Sm/Y)1.8 sample with CeO$_2$ additive were remarkably reduced and uniformly distributed within the superconducting (Sm/Y)1.8 matrix. Both samples, with/without $CeO_2$ additive, showed an onset Tc $\geq$ 90 K and sharp superconducting transition. The critical current density Jc value of the $CeO_2$ addictive were $1{\times}10^5A/\textrm{cm}^2$ in 77 K, 0 Tesla.

Preparation of YBa2Cu3O7-y Superconductor Using Melt Method (용융법에 의한 YBa2Cu3O7-y 초전도체 제작)

  • Lee, Sang Heon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.35 no.6
    • /
    • pp.622-625
    • /
    • 2022
  • YBa2Cu3O7-y bulk as a high temperature oxide superconducting conductor has the high critical temperature of 92 K. YBa2Cu3O7-y bulk superconductors have been fabricated by a seeded melting growth. Magnetic properties were studied by using superconductor of melted YBa2Cu3O7-y oxides. It was demonstrated that Y2BaCuO5 particles acts as a pinning center which plays an important role on the magnetic properties. The thickness of the upper and lower pellets of the YBa2Cu3O7-y bulk was formed at 40 mm with 55 g of the composition, and the YBa2Cu3O7-y superconductor was manufactured through a heat treatment process. Manufacturing the superconducting bulk, it is possible to improve the pore density of the superconducting bulk by providing a path through which oxygen could be emitted.

Preparation of Phase Pure Cuprate Superconductors via The Modification of Sol-Gel Method

  • Ahn, Beom-Shu
    • Journal of the Korean Applied Science and Technology
    • /
    • v.17 no.2
    • /
    • pp.144-148
    • /
    • 2000
  • A modification of the sol-gel method to obtain phase pure superconducting oxides is described. The method starts from organic salts of yttrium, barium and copper, such as acetates, and avoids the sudden and uncontrollable decomposition of the organic fraction which occurs if nitrates are used as starting materials. The aqueous solution obtained with citric acid in an alkaline medium is concentrated under vacuum. The solid so prepared is decomposed at about $300^{\circ}C$ thus giving an oxide precursor containing well dispersed yttrium, barium and copper. Pyrolysis at 850 - $920^{\circ}C$ followed by oxygen annealing gives the superconducting orthorhombic 123 phase. The results of TGA/DTA of the precursor, as well as XRD, electrical and magnetic property measurements on the pyrolysis products are presented and discussed.

Microstructure and Electrical Properties of (YNdSm)-Ba-Cu-O High Tc Composite Superconductors by Zone Melting Process (존멜팅법으로 제조한 (YNdSm)-Ba-Cu-O계 고온복합초전도체의 미세구조 및 전기적 특성)

  • Kim, So-Jung;Lee, Sang-Heon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.29 no.2
    • /
    • pp.110-113
    • /
    • 2016
  • (YNdSm)-Ba-Cu-O system high Tc composite superconductors were directionally grown by zone melting process, having large temperature gradient, in air atmosphere. Cylindrical green rods of $(YNdSm)_{1.8}Ba_{2.4}Cu_{3.4}O_x$ [(YNS)1.8]composite oxides by CIP (cold isostatic pressing) method using rubber mold were fabricated. The microstructure and superconducting properties were investigated by XRD, TEM and SQUID magnetometer. The size of nonsuperconducting $(YNdSm)_2BaCuO_5$ inclusions of the melt-textured (YNS)1.8 sample with $CeO_2$ additive were remarkably reduced and uniformly distributed within the superconducting (YNS)1.8 matrix. (YNS)1.8 samples, with / without $CeO_2$ additive, showed an onset $T_c{\geq}90K$ and sharp superconducting transition. The critical current density $J_c$ value of the (YNdSm)1.8 superconductor with $CeO_2$ additive were 840 A, $1.2{\times}104A/cm^2$ in 77 K, 0 Tesla by direct current transport method.

Flux Pinning Enhancement in Melt- Processed $(Y_{0.5}Nd_{0.25}Sm_{0.25})_{1.8}Ba_{2.4}Cu_{3.4}O_y$ Superconductors

  • Kim, So-Jung;Cheon, Nam-Young;Park, Jong-Kuk;Lee, Sang-Kyo;Shim, Sang-Heung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2005.07a
    • /
    • pp.280-281
    • /
    • 2005
  • We have studied the superconducting properties and flux pinning enhancement of $(Y_{0.5}Nd_{0.25}Sm_{0.25})_{1.8}Ba_{2.4}Cu_{3.4}O_y$ [(YNS)-1.8] composite oxides by melt growth process in air. A sample prepared by this method showed well-textured microstructure, and $(Y_{0.5}Nd_{0.25}Sm_{0.25})_2BaCuO_5$ [(YNS)211] nonsuperconducting particles were uniformly dispersed in large (YNS)123 superconducting matrix. The sample showed a sharp superconducting transition at 91 K. The magnetization measurements of the (YSN)-1.8 sample exhibited the enhanced flux pinning, compared with $YBa_2Cu_3O_y$ (Y-123) sample without Sm and Nd.

  • PDF

Ceramics superconducting Energy Materials (세라믹 에너지 재료)

  • Lee, Sang-Heon
    • Proceedings of the KIEE Conference
    • /
    • 2008.07a
    • /
    • pp.1238-1239
    • /
    • 2008
  • The high Tc supeconductor of ceramic oxides type was studied for finding its application field. The results reportaed in this paper on the stability of the ceramic superconductors and the resistance to ripening in the BCO liquid phase at elevated temperature opens a processing window for engineering the microstructure of large superconductor at the nanoscale level. The results suggest further that the introduction of highly efficient artifical pinning center to bulk ceramics superconductor.

  • PDF

Melt growth and superconducting properties of Sm-doped YBCO super-conductor by zone melting method (국부용융성장법으로 제조된 Sm이 첨가된 YBCO 초전도체의 용융온도 및 성장 속도에 따른 미세구조)

  • 김소정
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.14 no.2
    • /
    • pp.68-72
    • /
    • 2004
  • Sm-doped YBCO high $T_c$ superconductor was directionally grown by zone melt growth process in air atmosphere. Cylindrical green rods of $(Sm/Y)_{1.8}Ba_{2.4}Cu_{3.4}O_{7-x}$[(Sm/Y)1.8] oxides were fabricated by cold isostatic pressing (CIP) method using rubber mold. Based on the variation of melting temperature and growth rate, the microstructure and superconducting properties were systematically measured by using optical micrographs, TEM and SQUID magnetometer. In this study optimum melting temperature and growth rate were $1085^{\circ}C$ and 3.5 mm/hr respectively. Nonsuperconducting $(Sm/Y)_2BaCuO_5$ inclusions of (Sm/Y)1.8 superconductor were uniformly distributed within the superconducting (Sm/Y) $Ba_2Cu_3O^{7-x}$ matrix. The directionally melt-textured (Sm/Y)1.8 superconductor showed an onset $T_c$ $\geq$ 90K and sharp superconducting transition.

Microstructure of the (Nd/Y)-Ba-Cu-O superconductors by floating zone melt growth process (부유대역용융성장법을 이용한 (Nd/Y)-Ba-Cu-O계 초전도체의 미세구조)

  • 김소정
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.13 no.2
    • /
    • pp.83-87
    • /
    • 2003
  • $(Nd/Y)_{1.8}Ba_{}2.4Cu_{3.4}O_{7-x}$high $T_c$ superconductor was directionally grown by floating Bone melt growth process with a large temperature gradient in air. Cylindrical green rods of (Nd/Y)1.8 oxides were fabricated by cold isostatic pressing (CIP) method using rubber mold. Microstructures were observed by SEM and TEM and superconducting properties were measured by a SQUID magnetometer. Nonsuperconducting $(Nd/Y)_2BaCuO_5$ inclusions were uniformly distributed within the superconducting $(Nd/Y)Ba_2Cu_3O_x$ matrix. The directionally melt-textured (Nd/Y) 1.8 superconductor showed an onset Tc $\geq$ 90 K and a sharp superconducting transition.