Paramagnetic response in a Pb-porous glass nanocomposite superconductor

Dc magnetization studies (FC, ZFC, and hysteresis loops) were carried out for superconducting Pb-porous glass nanocomposite. Paramagnetic FC was observed at high fields. Within a temperature range, where superconductivity appeared only in a small part of the sample, the positive FC magnetization was found to coexist with the positive ZFC response while at lower temperatures ZFC was diamagnetic.