Effect of Bi deficiency on grain alignment of BiPb-2223 thin film fabricated using rf sputtering process and on critical current density properties

In the present study, thin films prepared as a function of the Bi concentration in the BiPbSrCaCuO system were synthesised. Thin films were fabricated using radio frequency sputtering method. Crystal structure of the films fabricated was determined from X-ray diffraction measurements. The crystal orientation was analysed by X-ray pole figure and in-plane alignment. Both X-ray diffraction and pole figure analysis revealed that crystallinity in the films decreased significantly with decreasing Bi concentration in the system. A systematic decrease in the superconducting transition temperature and hole concentration per CuO plane was obtained with decreasing Bi concentration. The J_c values of the films were calculated using Bean formula. It exhibits a significant dependence on the magnetic field and temperature. It was found that J_c decreased sharply with increasing applied magnetic field. The highest J_c value was found to be 1·06×10⁶ A cm⁻² at 10 K, which corresponded to the best flux pinning among the films fabricated.