The Irreversibility Fields of (Tl_0.5Pb_0.5) (Sr_0.85Ba_0.15)₂Ca₂Cu₃O_zFilm on Polished Silver Substrate

Abstract

Superconducting (Tl0.5Pb0.5)(Sr0.85Ba0.15)2Ca2Cu3Oz film was prepared on a highly polished, untextured silver substrate. A superconducting transition temperature (T 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 3 A/cm 2 at 77 K in the self field. This value is smaller than the value calculated from ac susceptibility data: 53 × 10 3 A/cm 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.

Study of Resistive Superconducting Transition of Thallium Based Superconductors

“…On the other hand, higher than 2/3 values of m suggest the pinning force is weak and the vortex structure is like in HTS. These results are consistent with the temperature dependence of the critical currents and of the irreversibility elds [15,16]. The interesting features of the broadening of the resistive transition may be observed in the (Tl 0.5 Pb 0.5 )Sr 2 (Ca 1−x Gd x )Cu 2 O z superconductors (see Fig.…”

STUDY OF THE STRUCTURAL AND ELECTRICAL EFFECTS OF THE T2−xAgxBa2Ca2Cu3O10+ SUPERCONDUCTING WITH PARTIAL REPLACEMENT OF SILVER WITH THALLIUM

“…After the discovery of some ceramic materials with a temperature of more than 90 K, which were referred to as high-temperature superconductors, superconductors entered a new stage. The ability to use liquid nitrogen for cooling [3] and liquid nitrogen at a temperature of (77 K), which can be obtained readily and at an affordable price [4,5], and the discovery of these materials have mad. When materials are cooled to a specific temperature, known as the critical temperature Tc, they become superconducting, allowing electric current to flow without resistance and with no magnetic flux at all.…”

“…Research is still going on to find superconducting materials with higher critical temperatures so that the applications are more readily available. Liquid nitrogen at a temperature (77 K), which can be obtained easily and at an appropriate cost [4,5], is another option. Tl-1223 was discovered to have two configurations in general: A pure compound is TlBa2Ca2Cu3O9 [6].…”

Effect of Partial Substitution of Sr by Ba on the Structural Properties of Tl_0.8Ni_0.2Sr_2-xBr_xCa₂Cu₃O_9-δ System

“…It is now known that partial substitution of the Tl +2 layer in the Tl-O layer by cations which have higher oxidation states than Hg +2 , Ni +2 , Bi +4 , Pb +4 , and Cu +3 [7][8][9][10]. It improves stability and makes the synthesis of the single-phase material readily possible, and it has been found that the partial substitution of Sb2O3 for Tl2O3 helps stabilize the composition of the high Tc superconducting material, thus increasing the fraction size of this phase.…”