摘要
Six different compositions in Bi2Sr2Ca2Cu3Oy:Sex with x=0.0, 0.05, 0.1, 0.2, 0.3, 0.4 have been prepared by the solid state reaction method to explore doping of selenium in the system. Sintering at 847±4℃ and subsequent annealing at 827℃ has been carried out for different time periods. The samples have been characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and measurement of resistance below room temperature has been carried out by four-probe method. Superconducting transition temperature (Tc) value shows dependence on Se concentration: the highest Tc(0)=:94 K is observed for x=0.3. A detailed Auger electron spectroscopic (AES) analysis has been carried out to investigate the presence of Se in the grains of the superconductors. It has also been found that Se increases the Tc(0) value and promotes the formation of high temperature superconducting phase (2223), which coexists with low temperature phase (2212) in the sintered samples.
Six different compositions in Bi2Sr2Ca2Cu3Oy:Sex with x=0.0, 0.05, 0.1, 0.2, 0.3, 0.4 have been prepared by the solid state reaction method to explore doping of selenium in the system. Sintering at 847±4℃ and subsequent annealing at 827℃ has been carried out for different time periods. The samples have been characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and measurement of resistance below room temperature has been carried out by four-probe method. Superconducting transition temperature (Tc) value shows dependence on Se concentration: the highest Tc(0)=:94 K is observed for x=0.3. A detailed Auger electron spectroscopic (AES) analysis has been carried out to investigate the presence of Se in the grains of the superconductors. It has also been found that Se increases the Tc(0) value and promotes the formation of high temperature superconducting phase (2223), which coexists with low temperature phase (2212) in the sintered samples.
