The effects of the post-annealing temperature on the growth mechanism of Bi2Sr2Ca1Cu2O8+ ∂ thin films produced on MgO (1 0 0) single crystal substrates by pulsed laser deposition (PLD)

The effects of post-annealing temperature were investigated on Bi 2Sr2Ca1Cu2O8+ ∂ thin films deposited on MgO (1 0 0) substrates by pulsed laser deposition (PLD). The structural and superconducting properties of the films have been determined by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), temperature dependent resistivity (R-T), and DC magnetization measurements. The films which were deposited at 600 C were post-annealed in an atmosphere of a gas mixture of Ar (93%) and O2 (7%), at temperature ranging between 800 and 880 C. This resulted in films which exhibited a single phase of 2212 with a high crystallinity (FWHM ≈ 0.16) and texturing along the c-axis, perpendicular to the plane of the substrate. An optimum temperature of 860 C was found for the post-annealing thermal treatment. The critical temperature, TC, of the films was measured as 82 K and the critical current density, JC, was calculated as 3 × 107 A/cm2 for the film annealed at 860 C.Research Fund of Cukurova University (FEF2011D20

Effect of Yttrium substitution on superconductivity in Bi-2212 textured rods prepared by a LFZ technique

In this study, the physical and superconducting properties of the Bi2Sr2Ca1-xYxCu2O8+delta with x=0.0, 0.05, 0.075 0.1, and 0.20 textured superconducting rods prepared by a laser floating zone technique were presented. The effects of Y3+ substitution for Ca2+ have been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), dc-magnetization, magnetic hysteresis and critical current density calculation by using the Bean''s critical state model. The powder XRD patterns of the samples have shown the Bi-2212 phase is the major one. Along with the powder samples, the textured rod surfaces also were investigated by XRD. The grains found to be well-oriented along the longitudinal rod axis which is a typical result for superconductors prepared by laser floating zone (LFZ) method, has been observed. The best critical temperature, T-C, has been found as 92.9 K for the sample with 0.15Y substitution, under DC magnetic field of 50 Oe in ZFC mode. It has also been observed that the critical current density decreases with increasing Y-substitution. Using those values, the maximum J(C) value has been determined as 2.37 x 10(5) A/cm(2) for the undoped sample

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 and Ag addition on the superconducting properties of Bi-2212 textured materials

The effect of Ag addition on the structural and superconducting properties of Bi2Sr2Ca0.925Na0.075Cu2Oy + x wt% Ag materials with x = 0, 1, 3, and 5 prepared by sol–gel method, followed by directional growth using the laser floating zone (LFZ) technique has been investigated. Powder XRD measurements demonstrate that all samples are composed by nearly single Bi-2212 phase. SEM micrographs and EDX results confirms that Bi-2212 is the major phase with minor amounts of a Bi-free one (Sr, Ca)CuO2 and metallic Ag. According to the magnetic results, Ag does not modify the superconducting critical temperature, Tc, but significantly increases the magnetic hysteresis loop area. The magnetic critical current density is maximum in the 3 wt% Ag containing samples, due to the larger grain clusters found in these samples, reaching 2.1 × 105 A/cm2 at 10 K. Moreover, Ag addition also improves the rods mechanical properties, determined by three point bending tests. The highest bending stress is also reached in the 3 wt% Ag samples

Improvement of structural and superconducting properties of Bi-2212 textured rods by substituting sodium

In this paper, the physical and superconducting properties of BiSrCaNaCuO with x=0.0, 0.05, 0.075, 0.1, and 0.20 textured superconducting fiber rods prepared by a laser floating zone (LFZ) technique were studied. The effects of Na substitution for Ca have been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transport measurements, dc-magnetization, magnetic hysteresis and magnetic critical current density. The powder XRD patterns of samples have indicated that Bi-2212 phase is the major one, independently of Na content. The best critical temperature, T, has been found as 93.3 K from M-T data for the sample with 0.075 Na substitution. The maximum magnetic J value has been calculated as 1.35×10 A/cm at 10 K for the 0.10 Na sample. The maximum transport critical current density has directly been measured as 1.3×10 A/cm at 77 K for the 0.05Na sample.This work is supported by Research Fund of Çukurova University, Adana, Turkey, under Grant contracts no: FBA-2015-3934. M. A. Madre and A. Sotelo wish to thank the Gobierno de Aragón and Fondo Social Europeo (Grupo de Investigacion Consolidado T12) and MINECO-FEDER (project MAT2013-46505-C3-1-R) for financial support. M. A. Madre also acknowledges funding from MINECO-FEDER (Project ENE2014-52105-R).Peer Reviewe

Effect of V substitution on vortex pinning and superconducting properties of Bi-2212 superconductor

In this work, the effect of Vanadium (V) substitution in the Bi2Sr2Ca1-xVxCu2O8+y superconductor with x = 0.0, 0.05, 0.1, 0.2, 0.3, and 0.4 has been investigated. The samples were prepared by a conventional solid state reaction technique. The effects of vanadium substitution have been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy, and magnetic characterizations. XRD patterns indicate that the Bi-(2212) phase is the major one for pure sample, but with increasing of V content, the volume fraction of Bi-2212 is reduced and transformed to mainly low-Tc phase, namely Bi-2201. 0.05 V substitution causes a remarkable increase of superconducting critical temperature as 86.2 K, which is higher than pure sample by 2.3 K. Moreover, 0.05 V leads to improvement of intragranular JC value which is calculated as 2.53 × 104 A/cm2 at 10 K. For comparison, the enhancement in JC value is about 78 % more than those value obtained for pure sample. The whisker structure with a length of 0.25 mm in main matrix is also observed in the SEM micrographs of 0.4 V substitution. © 2016, Springer Science+Business Media New York

The effects of the post-annealing time on the growth mechanism of Bi2Sr2Ca1Cu2O8+ thin films produced on MgO (100) single crystal substrates by pulsed laser deposition (PLD)

Bi2Sr2Ca1Cu2O8+?ï thin films were deposited on MgO (100) substrates by pulsed laser deposition (PLD). The effects of post-annealing time on the phase formation, the structural and superconducting properties of the films have been investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), temperature dependent resistivity (R-T), atomic force microscopy (AFM), and DC magnetization measurements. The films deposited at 600 °C were post-annealed in an atmosphere of a gas mixture of Ar (93%) and O2 (7%), at 860 °C for 10, 30, and 60 min. All films have demonstrated a mainly single phase of 2212 with a high crystallinity (FWHM0.159°) and c-axis oriented. The critical temperature, TC, of the films annealed for 10, 30, and 60 min were obtained as 77, 78, and 78 K, respectively. The highest critical current density, JC, was calculated as 3.34×107 A/cm2 for the film annealed at 860 °C for 30 min at 10 K. © 2016 Elsevier Ltd and Techna Group S.r.l.FEF2011D20This work is supported by Research Fund of Cukurova University , Adana, Turkey, under Grant no: FEF2011D20 . The authors gratefully acknowledge the Material Research Center of Izmir Institute of Technology, for their kind help and to the staff members of the Pulsed Laser Deposition Laboratory for the preparation and analysis of our films

The effects of the post-annealing time on the growth mechanism of Bi(2)Sr(2)CalCu(2)O(8-partial derivative) thin films produced on MgO (100) single crystal substrates by pulsed laser deposition (PLD)

WOS: 000370884500025Bi(2)Sr(2)CalCu(2)O(8+partial derivative) thin films were deposited on MgO (100) substrates by pulsed laser deposition (PLD). The effects of post-annealing time on the phase formation, the structural and superconducting properties of the films have been investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), temperature dependent resistivity (R-T), atomic force microscopy (AFM), and DC magnetization measurements. The films deposited at 600 degrees C were post-annealed in an atmosphere of a gas mixture of Ar (93%) and O-2 (7%), at 860 degrees C for 10, 30, and 60 min. All films have demonstrated a mainly single phase of 2212 with a high crystallinity (FWHM approximate to 0.159 degrees) and c-axis oriented. The critical temperature, T-C, of the films annealed for 10, 30, and 60 min were obtained as 77, 78, and 78 K, respectively. The highest critical current density, J(C), was calculated as 3.34 x 10(7) A/cm(2) for the film annealed at 860 degrees C for 30 min at 10 K. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.Research Fund of Cukurova University, Adana, TurkeyCukurova University [FEF2011D20]This work is supported by Research Fund of Cukurova University, Adana, Turkey, under Grant no: FEF2011D20. The authors gratefully acknowledge the Material Research Center of Izmir Institute of Technology, for their kind help and to the staff members of the Pulsed Laser Deposition Laboratory for the preparation and analysis of our films