Effect of doping by low content of yttrium at Ca and Sr sites of Bi(Pb)-2212 superconducting ceramics

Supercond. Sci. Technol.

et al. 2015

Polycrystalline bulks of Bi 2 Sr 2 Ca 1−x K x Cu 2.0 O 8+δ (Bi-2212) with x = 0, 0.05, 0.10 and 0.15 were fabricated by the spark plasma sintering technique. The influences of K doping on the microstructures, electronic structures, as well as the related superconducting properties, were systematically investigated. The XRD analyses confirmed that K + ions have successfully substituted into the matrix of Bi-2212, and lead to a systematical change of lattice parameters. Due to the change of thermodynamic properties, bulks with higher density, larger grain size and better texture structures were obtained after doping. Therefore, ac susceptibility measurement revealed the optimization of intergrain connections, which lead to the optimization of both selfand in-field critical current density, J c of this system. The optimization of microstructures also caused the enhancement of surface pinning. Based on the enhancements of both intergrain connections and flux pinning properties, an obvious improvement of critical current density was obtained with the optimal doping content of K = 0.05. Meanwhile, Bi-2212 single filament tapes with K doping content of 0 and 0.05 were also fabricated by the powder-in-tube process. The XRD patterns also proved the successful doping of K ions in the Bi-2212 matrix. The critical current density J c , measured by the transport method under the magnetic field from 0 to 20 T at 4.2 K, proved the effectiveness of K doping on the enhancement of flux pinning properties of Bi-2212.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Optimization of Bi-2212 high temperature superconductors by potassium substitution

Supercond. Sci. Technol.

et al. 2015

show abstract

“…Therefore, the superconducting critical parameters were effectively optimized. Rare earth (RE) elements doping on the Sr/Ca site of Bi-2212 were also studied [10,[23][24][25][26][27][28][29][30][31]. All the reported RE ions, such as Gd 3+ , Ho 3+ , Yb 3+ and Eu 3+ could work as effective pinning centers in the BSCCO system, thus obviously improved the critical current density.…”

Section: Introductionmentioning

confidence: 99%

Influences of Yb substitution on the intergrain connections and flux pinning properties of Bi-2212 superconductors

Physica C: Superconductivity and its Applications

et al. 2015

“…Therefore, the superconducting critical parameters were effectively optimized. Rare earth (RE) elements doping on the Sr/Ca site of Bi-2212 have also been studied [22][23][24][25][26][27][28][29][30][31]. RE ions, such as Gd 3?…”

Section: Introductionmentioning

confidence: 99%

Doping effects on Bi-2212 high temperature superconducting thick films

J Mater Sci: Mater Electron

et al. 2015