The Irreversibility Fields of (Tl0.5\text{}_{0.5}Pb0.5\text{}_{0.5}) (Sr0.85\text{}_{0.85}Ba0.15\text{}_{0.15})2\text{}_{2}Ca2\text{}_{2}Cu3\text{}_{3}Oz\text{}_{z} Film on Polished Silver Substrate

Superconducting (Tl$\text{}_{0.5}$Pb$\text{}_{0.5}$)(Sr$\text{}_{0.85}$Ba$\text{}_{0.15}$)$\text{}_{2}$Ca$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{z}$ film was prepared on a highly polished, untextured silver substrate. A superconducting transition temperature (T\text{}_{c,50%}) of 114.7±0.3 K was obtained from the resistance versus temperature measurements for different applied ac currents. The density of the critical current measured by transport method was found to be 11.4×10$\text{}^{3}$ A/cm$\text{}^{2}$ at 77 K in the self field. This value is smaller than the value calculated from ac susceptibility data: 53×10$\text{}^{3}$ A/cm$\text{}^{2}$ at 77 K. The magnetical broadening of the resistivity transition to the superconducting state was observed. The irreversibility fields of the thallium based film were obtained from magnetoresistive measurements for both parallel to the c-axis and parallel to the $ab$ plane showing the anisotropy according to the magnetic field direction. The irreversibility fields as a function of temperature were successfully fitted by the power law

The Irreversibility Fields of (Tl 0.5

Superconducting (Tl$\text{}_{0.5}$Pb$\text{}_{0.5}$)(Sr$\text{}_{0.85}$Ba$\text{}_{0.15}$)$\text{}_{2}$Ca$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{z}$ film was prepared on a highly polished, untextured silver substrate. A superconducting transition temperature (T\text{}_{c,50%}) of 114.7±0.3 K was obtained from the resistance versus temperature measurements for different applied ac currents. The density of the critical current measured by transport method was found to be 11.4×10$\text{}^{3}$ A/cm$\text{}^{2}$ at 77 K in the self field. This value is smaller than the value calculated from ac susceptibility data: 53×10$\text{}^{3}$ A/cm$\text{}^{2}$ at 77 K. The magnetical broadening of the resistivity transition to the superconducting state was observed. The irreversibility fields of the thallium based film were obtained from magnetoresistive measurements for both parallel to the c-axis and parallel to the $ab$ plane showing the anisotropy according to the magnetic field direction. The irreversibility fields as a function of temperature were successfully fitted by the power law