Formation of Bi-2212-based composites with submicrometre-grained (Sr, Ca)SnO3

Phase assemblage was investigated in the Bi-Sr-Ca-Cu-Sn-O system at tempera tures of Bi-2212 phase crystallization. It is found that the Sr1-xCaxSnO3 p hase (x = 0.1-0.2) is compatible with Bi-2212 as well as with Bi-2201, CuO, alkaline-earth metal cuprates and bismuthates. The solubility of Sn in Bi- 2212 is limited to low values. The superconducting composites Bi-2212-(Sr, Ca)SnO3 were prepared by melt crystallization using single precursor and mi xed precursor routes. The materials consisted of Bi-2212 matrix with submic ron (Sr, Ca)SnO3 grains included in Bi-2212 lamellas and agglomerated in be tween. The composites exhibited enhanced flux pinning at T = 60 K, while at 5 K the effect of (Sr, Ca)SnO3 addition was not revealed.