2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/18687Low frequency transport measurements are performed on GdSr$_2$RuCu$_2$O$_8$ pellets. The observed current-voltage curves are qualitatively explained in the framework of a simple phenomenological model accounting for coexistence of ferromagnetism and superconductivity in the sample. A Curie temperature $T_{cM}$=133 K and a superconducting critical temperature $T_{cS}$=18 K, with an onset temperature $T_{cO}$=33 K, are extracted from the analysis of the current-voltage curves.5 pages, 7 figuresSuperconductivitytext