Characterization of a Cylindrical Superconductor Disk Prepared by the Wet Technique with Microstructure Analysis and Levitation Force Measurements Using a Permanent Magnet

Abstract

The levitation force between a cylindrical superconducting disk (CSCD) and a permanent magnet (Bi = 0.15 T) in the zero-field-cooled (ZFC) regime has been investigated at liquid nitrogen temperature (77 K). The CSCD showed a lower repulsive force. It was considered that the changes in the levitation force are related to the grain orientation, the homogeneity, and the number of the pinning centers in the samples. From the structural analysis, it was found that the volume percentages of the Bi-2223 and Bi-2212 phase are 81% and 19% in the CSCD, respectively. The calculated a and c lattice parameters of the Bi-2212 and Bi-2223 phases are a=b= 5.4055 angstrom (Bi-2212), 5.4102 angstrom (Bi-2223), and c = 30.7522 angstrom (Bi-2212), 37.0327 angstrom (Bi-2223), respectively.