Abstract Details

Proof of Intercalation in High-temperature Superconductors of Bi-Pb-Sr-Ca-Cu-O System by XRD
Abstract ID	MAT-12
Presenter	Daniel  Loy
Presentation Type	Poster
Full Author List	Daniel Loy (1) , Juana Acrivos (1) , J. G. Chigvinadze (1)
Affiliations	(1) San José State University
Category	Materials Science
Abstract	The Bi-Sr-Ca-Cu-O (BISCO:2,2,n-1,n) system is one of the most promising materials for the technical application of high-temperature superconductivity (HTSC). Due to their layered crystal structure, and anisotropy, the HTSC are susceptible to many different types of phase transitions. BISCO is characterized by a 0.3nm per layer structure where an increase in the number of layers from 10 for (2201)to 14 for (2212) to 18 for (2223) which increases the superconducting transition temperature from 10 to 85 to 110K [1]. This suggests that there may be a relation between the c-axis increase and Tc in this system. However, intercalation of pyridine increases the c-axis of BISCO:2212 without changing Tc [2]. We have investigated a Bi-Pb-Sr-Ca-Cu-O, (Pb)BISCO with 15%Pb substitution for Bi (sample #2) by XRD at SSRL BL2-1, at room temperature with the purpose of determining its structure before and after intercalation with pyridine. This system is characterized by Tc=107K, and remains superconductive at temperatures where thermal fluctuations play a significant role because their energy is comparable to that of Abrikosov vortices, elastic and pinning energies [3], which are prerequisites for such phase transitions. On exposure to pyridine we measured an increase in the c-axis of 0.3nm in sample#2 which is characterized by equal amounts of BISCO:2212 and 2223 layer structure.
Footnotes	[1] J. M. Tarascon et al., Phys. Rev.B 38, 8885 (1988 [2] J. V. Acrivos and C. T.Lin, J. Phys. Colloque C5, 325 (1991) [3] J. G. Chigvinadze, A. A. Iashvili, T. V. Machaidze, Phys. Lett. A 300, 524 (2002).
Funding Acknowledgement	Henry and Camille Dreyfus Senior Award at SJSU, DOE at SSRL.