Phase diagram for (Tl0.5Pb0.5)(Ba0.2Sr0.8)2Ca2Cu3O8+δ (Tl-1223) polycrystalline sample with optimum oxygen content

Abstract The magnetic field–temperature phase diagram ( B – T ) of a optimally doped sample belong to (Tl 0.5 Pb 0.5 )(Ba 0.2 Sr 0.8 ) 2 Ca 2 Cu 3 O 8+ δ was studied thought resistivity and magnetization measurements. The phase diagram of this compound was built identifying four characteristic regions inside it. The thermally activated flux flow region (TAFF) followed both, the Yeshurum-Malozemoff and Tinkham's models. The magnetic field dependence of U eff does scale with B −0.5 signalising pinning mechanism similar to the ones found in Bi-2212.