2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/97148The magnetization of porous $Bi_{1.8}Pb_{0.3}Sr_2Ca_2Cu_3O_x$ have been investigated. The experimental magnetization hysteretic loops of $M(H)$ were described in the frames of Val'kov -- Khrustalev model developed for type II granular superconductors.3 pages, 1 figureSuperconductivityMagnetization loop and critical current of porous Bi-based HTSCtext