A systematic study of the effects of metal substitutions for Cu in YBa2(Cu1-xMx)3O7-δ, M = Fe, Co, Al,

A series of polycrystalline YBa2(Cu1-xMx)3O7-δ (1:2:3) samples with a typical grain size > 10 μm was prepared using well controlled and reproducible procedures. This relatively large grain size allowed microprobe studies of individual grains to determine M content of the 1:2:3 phase. In this paper solubility limits of substitutions for Cu in these samples are estimated. Superconducting transition temperatures and lattice parameters are presented. In the case of Ga, microprobe studies show no evidence for Ga content of 1:2:3 above x = 0.01. Preliminary studies show no evidence for solid solution above x=0.01 when substituting Mn, Cr, Zr, and Ti for Cu in 1:2:3