Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1608188 | Journal of Alloys and Compounds | 2015 | 6 Pages |
Abstract
A series of samples with the nominal composition of Bi2Sr2âxCaxCuO6+δ (x = 0.2, 0.4, 0.6, 0.8, 1.0) ceramics are synthesized by sol-gel growth. The microstructure and the incommensurate modulation structure (IMS) were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD) methods. The superconductivity and the onset temperature of superconducting transition (Tc,onset) were analysed. In the whole Ca-doping range, an IMS in bâ-câ planes can be identified and the values of Tc,onset are all exceed 80 K. With an increase of x, the b-component of modulation vector qâ, the basic structural parameters b and c of Bi-2201 phase have a trend of fall first then rise, whereas the c-component of modulation vector, the angle θ between qâ and bâ vectors and the values of Tc,onset are reversely varied. It can be verified that Ca concentration x = 0.6 is an extreme value, at which the distortion of the CuO2 layers makes the concentration of mobile carriers and the value of Tc,onset optimizing.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
B.Z. Sun, M. Zhang, R.Y. Wang, Y.L. Jiang, H. Wang, Y. Qi,