Partial-Melting of Filamentary Hg1223 Superconductors by Using CaHgO_2 for the Vaporizing Material

摘要

A partial melting of filamentary Hg1223 superconductors by using CaHgO_2 for the vaporizing material was examined. A filamentary Ba_2Ca_2Cu_3Re_(0.2)O_x precursor was spun by a solution spinning method and partially melted in an evacuated quartz tube with a pellet of (CaHgO_2)Ba_(1.8)Ca_1Cu_3Re_(0.2)(BaF_2)_(0.2)O_x as a reactor. Using CaHgO_2 enabled a rapid heating up to 920 deg C for partial-melting of the filamentary sample. The reacted sample was a nearly single phase of Hg1223 with T_c value of 135 K and the highest J_c value of 6000 A/cm~2 at 77 K and 0 T. Although the J_c value decreased, the improved microstructure of the sample was observed by controlling the heating condition.