• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.10a
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• pp.69-71
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• 2003

The magnetic field sensor was fabricated with superconducting ceramics of YBaCuO system. The sensor at liquid nitrogen temperature showed the increase of electrical resistance by applying magnetic field. Actually the voltage drop across the sensor was changed from zero to a value more than 100 $mutextrm{V}$ by the applied magnetic field. The change in electrical resistance depended on magnetic field. The sensitivity of this sensor was 2.9 $\Omega$/T. The sensing limit was about $1.5\times$10$^{-5}$. The increase of electrical resistance by the magnetic field was ascribed to a modification of the Josephson junctions due to the penetrating magnetic flux into the superconducting material. Considering the observed properties of the superconductor with trapped magnetic flux, a magnetic sensor was fabricated to detect simultaneously both the intensity and the direction of the magnetic field.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.717-720
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• 1992

Since the discovery of High-Tc superconducting Y-Ba-Cu-O ceramics with critical temperature of about 90K, numerous efforts to prepare supercond ucting thin films with excellent qualities such as High-Tc and critical current density have been made. The samples were deposited onto $SiO_x$ substrates heated at 540$^{\circ}C$ - 600$^{\circ}C$ in a single target rf - magnetron sputtering system. The film thickness has 2000$\AA$ - 5000 $\AA$ with a rate of 16 $\AA$/min. and distance between target and substrate was 50 mm. The films were characterized by X - ray diffraction, scanning electron microscopy and critical temperature.

• The Korean Journal of Ceramics
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• v.6 no.2
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• pp.164-167
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• 2000

The barium rich region of the Y-Ba-Cu-O-C system includes a tetragonal perovskite-like phase, which possesses a wide homogeneity region toward yttrium, copper and carbonate ion on the one hand, and toward oxygen, on the other hand. Accounting for vacancies ($\square$-vacancy) this phase could be described by the general formula per unit cell: {Ba$_8$}[Y$_{3-z}$Cu$_{5-x}$$(CO_3)_n$ $\square$$_{x+x-n}$]O$_{y{\pm}{\delta}y}$ (*). Here, cube-octahedral sites are represented in braces, while quasioctahedral ones with proper octahedral (Y, Cul), square (Cu2) and triangular (CO$_3$) configuration are shown in square brackets. The formula (*) was confirmed by full-profile Rietveld refinement based on X-ray diffraction data of YBa$_{5}$Cu$_2$O$_y$ (1-5-2 phase). Homogeneity region limits of the phase (*) at 96$0^{\circ}C$ in air were determined to be -0.33$\leq$x$\leq$1.80, 0.33$\leq$z$\leq$2.00, 0$\leq$n$\leq$3.

• Korean Journal of Materials Research
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• v.4 no.4
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• pp.401-405
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• 1994

The chemical composition and electrical properties were investigated for epitaxially crystallized $(Ba_{0.5}Sr_{0.5})Tio_3$ (BST) films deposited on Pt and $YBa_Cu_3O_{7-x}$(YBCO) electrodes by laser ablation technique. The crystalline quality of the heteroepitaxial BST films deposited on Pt bottom electrode was found to be better than that of BST film on YBCO electrode by the RBS analysis. Films deposited at $600^{\circ}C$ on Pt electrode showed a dielectric constant of 320 and a dissipation factor of 0.023 at 100kHz. Leakage current density of BST films on Pt electrode was smaller than that on YBCO bottom electrode. Their leakage current density was about 0.8$\mu \; A/ \textrm{cm}^2$ at an applied electric field of 0.15MV/cm.