Abstract:Precursor powders of Bi2.1Sr1.96CaCuxO8 d (Bi-2212) high temperature superconductors with different nominal Cu content of x=2.0, 2.1, 2.2 and 2.4 were fabricated by modified co-precipitation process. The influences of Cu contents on the phase evolution process during sintering were investigated systematically. Bi-2212 thick films and single filament tapes were fabricated with dip-coating process and powder in tube process, respectively. Obvious influences of Cu contents on the phase compositions, microstructures and superconducting properties were systematically discussed. It was noticed that the initial Cu content can affect the thermodynamic properties of Bi-2212 phase, thus lead to the change of phase evolution process. With the increase of Cu content, the phase content of Bi-2201 decreased, while the content of AEC phase increased. The maximum critical current density was obtained on the x=2.2 film and tape simultaneously due to the proper phase composition and better texture structures.