Effects of the Ba-substitution for Sr in the Bi-2201 phase of BiPb(Sr,La)₂CuO_6+δ

Synthesis of the Ba-substituted Bi-2212 phase of BiPb(Sr, Ba)2 RECu2O8

“…Very recently, we have successfully synthesized the partially Ba-substituted Bi-2201 phase by expanding Bi-O layer through the incorporation of extra oxygen ions or the partial substitution of larger Pb for smaller Bi. 17,18) This suggests that the reason why the Basubstitution is hard is that the size mismatch between the smaller Bi-O layer and the larger Sr-O layer is enhanced through the Ba-substitution. As for the Bi-2212 phase, Naumov et al 19) have reported the successful synthesis of the Ba-substituted Bi-2212 phase, Bi 2 Ba 2 NdCu 2 O 8+δ in which the Bi-O layer is expanded by the incorporation of a large amount of extra oxygen ions through the Nd 3+ -substitution for Ca 2+ .…”