Effect of Na substitution on superconducting properties of Bi-2212 ceramics prepared by Sinter-Forged process

Bulk textured Bi2Sr2Ca1-xNaxCu2Oy (x = 0.0, 0.05, 0.075 0.1, 0.15, and 0.20) ceramics have been prepared by a polymer solution method followed by sinter-forging process. The microstructure and superconducting properties of textured samples were affected by Na substitution. According to XRD data, all samples show that Bi-2212 phase is the major one, and main peaks corresponded to the (00l) diffractions confirming that the crystallographic c-axis is perpendicular to the surface. SEM micrographs showed that samples are composed of well-stacked and oriented grains. The best critical temperature, TC, was measured as 85.6 K for x = 0.075. The critical current density Jc, values decrease gradually with the increase of applied magnetic field. The maximum calculated Jc was 1.38 × 105 A/cm2 at 10 K for 0.075 Na sample which is about four times higher than the 0.34 × 105 A/cm2 value determined for the pure sample. The anisotropic properties of these textured materials have been investigated using magnetic measurements

Effect of Na substitution on superconducting properties of Bi-2212 ceramics prepared by Sinter-Forged process

Bulk textured Bi2Sr2Ca1-xNaxCu2Oy (x = 0.0, 0.05, 0.075 0.1, 0.15, and 0.20) ceramics have been prepared by a polymer solution method followed by sinter-forging process. The microstructure and superconducting properties of textured samples were affected by Na substitution. According to XRD data, all samples show that Bi-2212 phase is the major one, and main peaks corresponded to the (00l) diffractions confirming that the crystallographic c-axis is perpendicular to the surface. SEM micrographs showed that samples are composed of well-stacked and oriented grains. The best critical temperature, TC, was measured as 85.6 K for x = 0.075. The critical current density Jc, values decrease gradually with the increase of applied magnetic field. The maximum calculated Jc was 1.38 × 105 A/cm2 at 10 K for 0.075 Na sample which is about four times higher than the 0.34 × 105 A/cm2 value determined for the pure sample. The anisotropic properties of these textured materials have been investigated using magnetic measurements. © 2016 Elsevier LtdGobierno de Aragón MAT2013-46505-C3-1-R, ENE2014-52105-R MF2014BAP1 FBA-2014-3500 T12This work is supported by Research Fund of Çukurova University, Adana, Turkey , under grant contracts no: FBA-2014-3500 . A. Sotelo and M.A. Madre acknowledge the Gobierno de Aragón and Fondo Social Europeo (Grupo de Investigacion Consolidado T12) and MINECO-FEDER ( MAT2013-46505-C3-1-R ) for financial support. M.A. Madre also acknowledges MINECO-FEDER (Project ENE2014-52105-R) for funding. Authors would like to acknowledge the use of Servicio General de Apoyo a la Investigación-SAI, Universidad de Zaragoza. This work is also supported by Research Fund of Hakkari University, Turkey , under grant contracts no: MF2014BAP1