IRREVERSIBILITY LINE AND CRITICAL-CURRENT DENSITIES OF 1223-CUPRATE TLBA2CA2CU3O9 - A SINGLE-CRYSTAL STUDY

This paper reports for the first time on the pinning properties of a T lBa2Ca2Cu3O9 single crystal. The irreversibility line and the critical current densities have been determined by magnetic measurements in th e configuration H//c. The location of the irreversibility line in the (H, T/T-c) plane and the values of critical current densities have bee n found to be higher than in previous studies on single crystals of al l the other phases belonging to the same Tl-Ba-Ca-Cu-O system. The irr eversibility lines of the Tl-monolayer cuprates are located above thos e of the Tl-bilayer cuprates. Moreover, a systematic steepening of the irreversibility line as the thickness of the CuO2 multilayer is incre ased is in evidence. These results are discussed on the basis of the J osephson decoupling model proposed by Kim et al.