Improvement of magnetic properties in Bi-2212 ceramics by fluorine doping

• Published in: Solid state sciences 2005, Vol.7 (1), p.53-57
• Main Authors: Amira, A., Mosbah, M.F., Molinié, P., Leblanc, A.
• Format: Article
• Language: English
• Subjects: Bi-2212 phase; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Critical current density; Critical transition temperature; Crystalline state (including molecular motions in solids); Cuprates superconductors (high tc and insulating parent compounds); Exact sciences and technology; Fluorine doping; Magnetic properties and materials; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Superconductivity; Theory of crystal structure, crystal symmetry; calculations and modeling
• ISSN: 1293-2558; 1873-3085
• DOI: 10.1016/j.solidstatesciences.2004.10.036

Superconducting ceramics of Bi 2Sr 2CaCu 2O y F x with x = 0 , 0.2 and 0.4 are prepared by conventional solid state reaction. They are characterized by means of XRD, SEM, EDX and magnetic measurements. Unlike the low temperature fluorination method described by other authors, the study shows that the superconducting volume fraction of samples increases gradually with fluorine doping. The critical transition temperature is observed to be constant in all samples suggesting that fluorine substitution do not affect the CuO 2 planes. Hysteresis loops measured at 5 and 50 K indicate an improvement of the irreversible magnetization of the samples as fluorine content is increased. The deduced critical current density follows the same variation. At 50 K and 1 kG, this current vanishes in the undoped sample while it persist in the doped ones.