2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/30104We have identified ferromagnetic- and superconducting-like magnetization hysteresis loops in highly oriented pyrolytic graphite samples below and above room temperature. We also found that both behaviors are very sensitive to low-temperature -- as compared to the sample synthesis temperature -- heat treatment. The possible contribution of magnetic impurities and why these do not appear to be the reason for the observed phenomena is discussed.12 pages, 8 figures. Submitted to J. Low Temp. Phys. (Rapid Commun.) the 26.11.99.- First replacement: name in \ack correctedStrongly Correlated ElectronsSuperconductivitytext