Magnetic hysteresis of the zero-resistance critical temperature of high-Tc granular superconductors

The authors have found a notorious hysteretic behavior in the dependence of the zero-resistance critical temperature obtained through resistivity (ρ) versus temperature (T) measurements with applied field (Hc) in High-Tc granular superconductors. This behavior is explained semi-quantitatively based on the analogy between the present observation and a similar hysteresis found in the field dependence of the transport critical current in these materials