Alternative modeling of resistance versus temperature curves along the c direction of Bi-2212 crystals, suggesting a possible metal/insulator transition below Tc

Resistivity versus temperature curves of ''semiconducting like'' Bi-2212 crystals, in the normal state, along the c axis have been modelized by: rho = rho(0) exp {Delta/K(T-Ti)}, introducing a Ti temperature for which the resistivity is infinite. The excellent fit which is obtained (better than what had been previously obtained without introducing Ti) suggests a possible metal/insulator transition along the c axis at T = Ti. But Ti is below Tc, the superconducting transition temperature, so that, below Ti, superconducting crystals would be insulators in the normal state and direct insulator/superconductor transition could be observed.