  The magnetization of superconducting samples is influenced by their porosity.
In addition to structural modifications and improved cooling, the presence of
pores also plays a role in trapping magnetic flux. Pores have an impact on the
irreversibility field, the full penetration field, and the remnant
magnetization. Generally, as porosity increases, these parameters tend to
decrease. However, in the case of mesoscopic samples or samples with low
critical current densities, increased porosity can actually enhance the
trapping of magnetic flux.

Superconductivity;Materials Science