Growth of Bi2Sr2CaCu2O8+δ thin films with enhanced superconducting properties by incorporating NiO nanoparticles

A series of Bi2Sr2CaCu2O8+δ–xNiO (x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5) thin films were prepared by Pechini sol-gel method. With the doping of NiO, the microstructure and superconducting properties of thin films samples were characterized and analyzed particularly. All main peaks in XRD patterns corresponded to the (00l) diffraction peaks of Bi2212, demonstrating an excellent c-axis epitaxial growth of thin films samples. The second phase primarily existed in the form of highly textured with (200) epitaxy NiO crystal. Meanwhile, it was found that both Bi2212 matrix and NiO phase are characteristic of in-plane four-axis symmetry and the in-plane orientation relationship among the NiO phase, the Bi2212 matrix and the STO substrate can be determined to be Bi2212[100](001)//NiO[011](100)//STO[011](100). The effects of the doped NiO on the anisotropy of Bi2212 crystal growth is not significant. In addition, it was concluded that the zero resistivity superconducting transition temperature (Tc, zero) was decreasing with increasing doping level x, as well as thin films sample N2 (x = 0.2) exhibited the best current carrying capacity in magnetic field.