Papers by Keyword: Critical Currents

Abstract: Tapes of Ag/Bi2212 (Bi₂Sr₂CaCu₂O_8+δ) have been revealed as promising materials for superconducting applications at low temperatures (4.2 K using liquid helium or 20 K using a cryocooler) and high fields (above 10 T). The reaction and formation of phases are related to the ceramic densification and to the alignment of the grains, important for the improvement of the superconductor transport properties. In the present work, it is analyzed the influence of long isotherms at the temperature of 830 °C on the superconducting properties of Ag/Bi2212 samples. The heat treatments consisted of the use of two maximum temperatures of treatment (890 °C and 905 °C), with two different soaking times, both with an annealing isotherm at 830 °C for 5 h, 30 h, and 50 h.

Abstract: We have studied the impact of simultaneous Ba²⁺ doping at Sm³⁺ site (hole doping) and F^- doping at O^2- site (electron doping) on the structural and superconducting properties of Sm1111 system using a single source, BaF₂. With BaF₂ doping the extent of layering of the grains and the grain size have been improved considerably. High transport current of 875 A/cm² at 12 K has been achieved for the doped sample. The binary doped sample shows higher T_C of 51 K than the corresponding F-alone doped sample. In addition, substantially high values of H_C2 and better J_C-H behavior are observed for the BaF₂ doped samples. These results strongly indicate the scope for SmFeAsO based conductors with higher current carrying capacity.