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Oh, S.Y.;Hyun, O.B.;Kim, Chan-Joong
- Progress in Superconductivity
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- v.7 no.2
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- pp.179-183
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- 2006
As a material for SFCL(Superconducting Fault Current Limiter), BSCCO tube with metal stabilizer is a promising candidate, assuring the stability and large power capacity, For the application, the proper soldering technique, which overcome the difficulties of the joining between BSCCO and metal stabilizer, is required. In this study, after soldering In-Bi solder and In-Sn solder with BSCCO superconductor, welding properties between BSCCO and solders were investigated. Because ceramic materials is difficult to weld, Ag electro-plating on BSCCO 2212 is used for intermetallic layer. To find out the best welding condition for superconductor, soldering is tested in the maximum temperature from $155^{\circ}C\;to\;165^{\circ}C$ in the reflow oven. By investigating the composition and thickness of IMC (lntermetallic Compound) created in the reaction of Ag with solder, we analyzed the welding properties of High-Tc superconductor from a micro point of view.
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Song, K.J.;Lee, N.J.;Ko, R.K.;Park, C;Ha, H.S.;Ha, D.W.;Oh, S.S.;Kwon, Y.K
- Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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- 2002.02a
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- pp.168-170
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- 2002
Magnetization studies were conducted on a single crystal of $YNi_{2}$$B_{2}$C superconductor. The 17 mg crystal was studied at temperatures T from above $T_{c}$ (15.5 K) to 3 K, in the magnetic fields H // c-axis up to 6 tesla. The crystal exhibited little magnetic irreversibility, with a critical current density $CO_{3}$ ~ $10^{-4}$ $\times$ $CO_{3}$, the depairing current density. Near $T_{c}$, the equilibrium magnetization M was London-like with M $\infty$ In(H). The upper critical field $H_{c2}$ of the single crystal $YNi_{2}$$B_{2}$C was estimated by the several alternative approaches such as standard London limit, Ginzburg-Landau, and Abrikosov relations. The estimated $H_{c2}$values agree relatively well with each other approaches.
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이용우;김진수;박민석;이성익;심지훈;민병일;최은집
- Progress in Superconductivity
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- v.4 no.2
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- pp.144-147
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- 2003
We investigated superconducting property of ($Mg_{1-x}$$Zn_{x}$)$CNi_3$ (x=0,0.03, 0.06, 0.09, 0.12, 0.15, and 0.18) sample where Mg is substituted with Zn. The samples were synthesized us ins the solid state reaction method under As atmosphere. X -ray diffraction spectra show that the $MgCNi_3$ structure is maintained up to x=18. With increasing x, the lattice constant (or the Ni-Ni distance) decreases. Magnetic susceptibility measurement shows that $T_{c}$ decreases systematically with x and becomes ～2K at x =0.18. Surprisingly, the transition width remains sharp (～0.3K). Under some assumptions, we estimate the coupling constant in the McMillan formula as a function of x which we interpret in terms of the BCS theory.y.y.y.
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