ABSTRACT The effect of Arsenic substitution on the properties of Bi-2212 superconductors was studied. Solid-state reaction technique was used for the synthesis of Bi2−xAsxSr2Ca1.1Cu2.1O8 samples, x = 0, 0.1, 0.2 and 0.4. The X-ray diffraction confirmed the formation of the tetragonal phase of Bi-2212 superconductors. The decrement in the c parameter confirmed that As insertions were introduced into the Bi sites of the system. The grain morphology of the surface was analysed by scanning electron microscopy, where the amount of arsenic increases with As substitution. The superconducting transition temperature (Tc) was determined from the DC-electrical resistivity by the standard four-probe technique. Tc was enhanced up to x = 0.1 above which it was suppressed. For magnetism, half magnetic-hysteresis loops were obtained by SQUID magnetometer at different temperatures (5 and 30 K). The hysteresis loops sizes increased with increasing As-concentrations. The critical current density (Jc) and the flux pinning mechanisms were investigated via different models.

中文翻译：

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砷取代对 Bi-2212 超导体物理、电和磁性能的研究

摘要 研究了砷取代对 Bi-2212 超导体性能的影响。固态反应技术用于合成 Bi2−xAsxSr2Ca1.1Cu2.1O8 样品，x = 0、0.1、0.2 和 0.4。X 射线衍射证实了 Bi-2212 超导体的四方相的形成。c 参数的减少证实了 As 插入被引入系统的 Bi 位点。通过扫描电子显微镜分析表面的晶粒形态，其中砷的量随着 As 取代而增加。超导转变温度 (Tc) 是通过标准四探针技术从直流电阻率确定的。Tc 被增强到 x = 0.1，高于它被抑制。对于磁力，SQUID 磁力计在不同温度（5 和 30 K）下获得了半磁滞回线。磁滞回线尺寸随着砷浓度的增加而增加。通过不同的模型研究了临界电流密度 (Jc) 和磁通钉扎机制。