The superconductivity of pseudo-quternary system Y1−xMx Ba2 Cu3 O7-δ, YBa2 Cu3−xM x O7-δ, where M stands Co,Cr,&Zn and with x=0,0.001,0.005,0.01 & 0.02, has been investigated.
The XRD analysis shows that the perovskite structure is preserved and a stabilization effect on orthorhombic structure by 3d elements addition was proposed. On the contrary, the microstructure has been modified prominently and it is determined by the sintering mechanism involved and/or diffusion process in each doped sample. Second phase precipitate can be found at grain surface. The superconductivity, however, has not been greatly affected.