|Processing, structure and properties of directionally solidified YBa2Cu3O7-x superconductor (in Slovak)|
vol. 35 (1997), no. 3, pp. 174 - 187
Processing, structure and some physical properties of directionally solidified high temperature ceramic superconductor of YBa2Cu3O7-x + 20 wt.% Y2BaCuO5 type are reported. The structure of directionally solidified superconductors consisted of several grains with a - b planes oriented along the axis of the samples. The microstructure of the grains consisted of YBa2Cu3O7-x parallel plates and Y2BaCuO5 particles with a mean diameter of 2.1 × 10-6 m. After heat treatments in a dynamic oxygen atmosphere the critical temperature was measured to be Tc = 91 ± K. From magnetic measurements, critical current density Jc at 77 K in a direction parallel to a - b planes was determined to be 5 × 104 A cm-2 in zero magnetic field. In magnetic fields parallel to c axis (B || c), the Jc values significantly decreased to 11.9 x 103 and 1 × 103 A cm-2 at B = 0.15 and 4 T, respectively. In magnetic fields perpendicular to c axis (B || c), the Jc values of 3 × 103 and 1.3 × 103 A cm-2 were measured at 0.15 and 4 T, respectively.
processing, structure, physical properties, YBa2Cu3O7-x superconductor
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