Enhancement in superconducting properties of Bi2Sr2Ca1Cu2O8+θ (Bi-2212) by means of boron oxide additive

Highlights: • We investigated the effect of sintering temperature on the microstructure and superconducting properties of Bi₂Sr₂Ca₁Cu₂O_8+θ(Bi-2212) realized via solid state method. • The samples were investigated using several characterization techniques, including MAUD, XRD, FESEM/EDS and magnetic measurements. • The best superconducting properties are obtained for Bi-2212 sintered at 840 °C showing well ordered crystal structure, close to theoretical one. • Based on these findings, we studied the influence of several amounts of boron oxide additives on the properties of Bi₂Sr₂Ca₁Cu₂B_xO_y. • We found significant improvements of the samples microstructural and superconducting properties for an optimum Boron oxide amount of x = 0.05. - Abstract: By using a solid state method, Bi₂Sr₂Ca₁Cu₂O_8+θ (Bi-2212) polycrystalline samples were synthesized with the addition of boron oxide additive, with the aim of improving the performance of this compound for large scale applications. As the first step, the parameters for the solid state method, in particular sintering temperature, were optimized in order to obtain pure Bi-2212 samples with an optimal microstructure. Then, based on this optimization, the properties of the Bi₂Sr₂Ca₁Cu₂B_xO_y samples with x = 0.05, 0.1, and 0.2 were studied using several characterization techniques. It was found that the sample having x = 0.05 showed a magnetic hysteresis loop larger than that of the pure Bi-2212 sample and a critical current density value of 3.71 × 10⁵ A/cm², comparable to the best results found in the literature for Bi-2212, while preserving well-stacked and oriented grains.