• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.327-330
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• 2001

Phase intergrowth in BSCCO thin films have been investigated. It turned out from XRD analyses of these phases that molar fraction of each constituent phase in the intergrowth thin film can be exhibited as a function of substrate temperature and ozone pressure. Superconducting behavior of the intergrowth thin film is also discussed.

• 한국초전도학회:학술대회논문집
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• 2008.08a
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• pp.46-46
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• 2008

• Transactions on Electrical and Electronic Materials
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• v.2 no.4
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• pp.11-14
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• 2001

Phase intergrowth in BSCCO thin films has been Investigated. It turfed out from XRD analyses of these phases that molar fraction of each constituent phase in the intergrowth thin film can be exhibited as a function of substrate temperature and ozone pressure. Super- conducting behavior of the intergrowth thin aim Is also discussed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.517-520
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• 2007

The BSCCO thin film fabricated by using the layer by layer deposition method was compared with the BSCCO thin film fabricated by using the evaporation method. Reevaporation in the form of Bi atoms or $Bi_2O_3$molecules easily bring out the deficiency of Bi atoms in thin film due to the long sputtering time of the layer by layer deposition. On the other hand, the respective atom numbers corresponding to BSCCO phase is concurrently supplied on the film surface in the evaporation deposition process and leads to BSCCO phase formation. Also, it is cofirmed that by optimizing the deposition condition, each single phase of the Bi2201 phase and the Bi2212 phase can be fabricated, the sticking coefficient of Bi element is clearly related to the changing of substrate temperature and the formation of the Bi2212 phase.

• Progress in Superconductivity and Cryogenics
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• v.21 no.4
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• pp.9-12
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• 2019

We performed Raman spectroscopy on two different over-doped Bi₂Sr₂CaCu₂O_8+x (BSCCO), of which superconducting transition temperatures are 89 K and 77 K. Line-shape analysis of the Raman-spectrum was done, focused on B_1g bond buckling mode which have drawn a lot of attention, since photoemission studies showed an evidence for strong coupling between the mode and electron. The line-shapes show asymmetry and are well fitted by the Fano line-shape formula. Remarkably, we found that the peak line-widths from B_1g bond buckling mode in BSCCO show much broader than those in YBa₂Cu₃O_7-x. The broad line width can be attributed to the superstructure modulation of BSCCO. Our results imply that B_1g bond buckling mode may have close relation to the origin of superconductivity or to boosting the superconducting transition temperature in BSCCO.

• Progress in Superconductivity and Cryogenics
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• v.5 no.3
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• pp.30-33
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• 2003

1MVA high temperature superconducting (HTS) transformer with double pancake windings made of BSCCO-2223 HTS tapes was designed and manufactured. And prototype transformer with the same capacity was manufactured also. The each rated voltage of the HTS transformer is 22.9 kV and 6.6 kV. Four parallel BSCCO-2223 HTS tapes were wound in the double pancake windings of low voltage side. In order to distribute the currents equally in each HTS tapes, the three times transposition was performed between the double pancake windings. The windings of prototype transformer were wound using copper tape with the same size as BSCCO-2223 HTS tape. The core of the transformer was designed and manufactured as a shell type core made of laminated silicon steel plate. The several characteristics tests for the prototype transformer were performed in liquid nitrogen and insulation tests were accomplished also.

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.329-333
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• 1999

The BSCCO 2223 Ag-sheathed tapes were prepared with spray dried precursor powders, which are of different starting condition. The J$_c$ in the short tapes varied from 24 kA/ cm$^2$ to 47 kA/ cm$^2$ at 77K and 0T. The largely improvement of J$_c$ in certain tape, which characterized with the large textured BSCCO 2223 grains, homogeneity of reactant and fewer tracks of second phases in final superconducting matrixes, could be due to optimization in the precursor powder.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2001.02a
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• pp.72-75
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• 2001

The persistent current mode operation of HTS coils is one of the key technologies required for very high-field MRI magnets composed of LTS and HTS coils. But to date, the fabrication of persistent current mode system using HTS is not investigated well. In this paper, we fabricated the magnet and PCS using by BSCCO-2223 tape and jointed them with solder. The current decay behavior of the circuit was measured in liquid nitrogen by monitoring the magnetic field in the centre of magnet with a Hall sensor. To enhance the characteristic of persistent current mode system, superconducting joint method should be investigated.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.11
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• pp.997-1002
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• 2002

BSCCO thin films are fabricated by an ion beam sputtering method, and sticking coefficients of the respective elements are evaluated. The sticking coefficient of Bi element in BSCCO film formation was observed to show a unique temperature dependence; it was almost a constant value of 0.49 below about 730$^{\circ}C$ and decreased linearly over about 730$^{\circ}C$ In contrast, Sr and Ca, displayed no such remarkable temperature dependence. This behavior of the sticking coefficient was explained consistently on the basis of the evaporation and sublimation processes of Bi$\sub$2/O$\sub$3/. It was concluded that Bi(2212) thin film constructs from the partial melted Bi(2201) phase with the aid of the liquid phase of Bi$\sub$2/O$\sub$3/.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.929-931
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• 1999

BSCCO thin films have been fabricated by co-deposition at an ultralow growth rate using ion beam sputtering(IBS) method. Bi 2212 phase appeared in the temperature range of 750 and $795^{\circ}C$ and single phase of Bi 2201 existed in the lower region than $785^{\circ}C$. Whereas, ozone gas pressure dependance on structural formation was scarcely observed regardless of the pressure variation. And high quality of c-axis oriented Bi 2212 thin film with $T_c$(onset) of about 90 K and $T_c$(zero) of about 45 K is obtained. Only a small amount of CuO in some films was observed as impurity, and no impurity phase such as $CaCuO_2$ was observed in all of the obtained films.