Li substitution in Bi-2223 superconductors

In this study, the effects of Li doping on the the properties of high temperature superconductor Bi1.7Pb0.3Sr2Ca2Cu3-xLixOy was investigated. The samples were prepared by substituting Li (x= 0.00-0.20) for Cu with changing ratios by solid state reaction method. The effect of Li doping on the BPSCCO superconductor composite was examined by resistancetemperature, magnetic susceptibility-temperature and density measurements. The electrical resistance measurements were made by standard four-probe method. The effects of doping material on the superconducting transition temperature of samples were determined with these measurements. The magnetic susceptibility measurement was made by mutual inductance method. Diamagnetic transitions were determined by susceptibility measurements. Moreover, superconducting and impurity phases which the samples involve were determined by X-Ray diffraction patterns (XRD). The microstructure of the samples was analyzed with the help of scanning electron microscope (SEM). We observed from the results that all the doped samples had a critical temperature in the range of 89-98 K and Bi-2223 phase ratio is higher in lithium doped samples in respect of the un-doped sample.