## Abstract

A macroscopic observation of a magnetic flux distribution on the surface of a superconducting bulk material was performed. First, a single-domained thin rectangular YBCO sample (10 mm×10mm×1mm) was field-cooled in liquid nitrogen. After the applied field was turned off, a field distribution in the area of 10mm×10mm was mapped by scanning the sample surface at intervals of 0.5mm using a Hall probe fixed to a XY-stage. The obtained field distribution was visualized into a three-dimensional distribution map and a two-dimensional contour graph. The overall shape of the field distribution had a four-fold symmetry reflected by the sample geometry. Next, assuming that the critical current density Jcis independent of the field strength, a field distribution generated by square current loops was calculated numerically. The intragranular Jcwas estimated to be 2.6×104A/cm2 (77K, 0T) by fitting the calculated profile to the measured profile. Finally, it is found that the measurement of field distributions on the surface of a superconductor using a Hall probe is applicable to an estimation of an ntragranular Jcfor a superconductor without destroying the samples.

Original language | English |
---|---|

Pages (from-to) | 1818-1821 |

Number of pages | 4 |

Journal | IEEE Transactions on Applied Superconductivity |

Volume | 5 |

Issue number | 2 |

DOIs | |

Publication status | Published - 1995 Jun |

Externally published | Yes |

## ASJC Scopus subject areas

- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering