Observation of magnetic field lines in the vicinity of a superconductor with the naked eye

TL;DR

This paper visually demonstrates the Meissner and pinning effects in a high-temperature superconductor using colored wires, making magnetic field lines observable to the naked eye.

Contribution

It provides a simple, visual method to observe magnetic field phenomena in superconductors without specialized equipment.

Findings

Magnetic field lines are excluded from the superconductor (Meissner effect).

Magnetic flux is pinned within the superconductor (pinning effect).

Visual observation confirms theoretical predictions of superconductor behavior.

Abstract

Meissner effect and pinning effect are clearly observed with the naked eye. A GdBaCuO high-temperature superconductor (HTS) disk fabricated by Nippon Steel Corporation, a 100mm cubic NdFeB sintered magnet, and iron wires coated by colored are used. When the HTS is put in the magnetic field of the magnet, it can be observed by the wires that the magnetic field lines are excluded from the superconductor (Meissner effect) as well as are pinned in the superconductor (pinning effect).