The Effect of Mn Substitution on Properties of Bi1.6Pb0.4Sr2Ca2−x Mn x Cu3O y Superconductors

Abstract

The effects of Mn substitution on the physical properties and structural characteristics of Bi1.6Pb0.4Sr2Ca2Cu3−xMnxOy (Bi-2223) superconductor system have been studied. For this, the samples of nominal composition Bi1.6Pb0.4Sr2Ca2Cu3−xMnxOy (x=0.00, 0.10, 0.15 & 0.20) was prepared by the solid-state reaction method. It has been found that the effects of Mn substitution favor the formation of Bi-2223 phases. The phase identification/gross structural characteristics of synthesized (HTSC) materials explored through powder X-ray diffractometer reveals that all the samples crystallize in orthorhombic structure with lattice parameters (a=5.4918 A, b=5.4071 A, and c=37.0608 A) up to Mn concentration of x=0.20. The critical transition temperature (Tc) measured by standard four probe method has been found to depress from 108 K to 70 K and transport current density (Jc) has been increased from 4.67×102 to 3.52×103 A cm−2 as Mn content (x) increases from 0.00 to 0.20. The surface morphology investigated through scanning electron microscope and atomic force microscopy (SEM and AFM) results that voids and grains size increases as the Mn concentration increases besides the nanosphere like structures on the surface of the Mn doped Bi-2223 sample.