EVOLUTION OF THE (IR)REVERSIBILITY DOMAIN EXTENSION WITH T-C IN THE OVERDOPED TL-2201 HIGH-TC SUPERCONDUCTOR

A serie of the TI-2201 cuprate with T-c ranging from similar to 40 K t o 92 K with tetragonal as well as orthorhombic symmetry has been prepa red and their differential magnetic susceptibility chi'(H) measured un der static field up to 2 Tesla. Independently of the criteria defining the irreversibility onset, we show that the extension of the reversib le regime in the (H,T/T-c) diagram increases with T-c. Thus, contrary to what has been observed for YBa2Cu3O6+x where the reversibility doma in was enlarged with the T-c decreasing, here for low T-c the reversib ility domain is more limited and shifted toward H-c2(T) line. These re sults are discussed taking into consideration the evolution of lambda and the possible evolution of xi with T-c in this Cu-O monolayer overd oped HTS.