Determination of the line irreversibility in the new superconductor system Lu3-xGaxBa5Cu8Oy (x=0, 1.2, 1.5 y 3)

International Conference and Exhibition on Mesoscopic & Condensed Matter Physics

June 22-24, 2015 Boston, USA

D Castellanos, I Supelano and C A Parra Vargas

Universidad Pedag�³gica y Tecnol�³gica de Colombia, Colombia

Posters-Accepted Abstracts: J Material Sci Eng

Abstract :

The irreversibility properties of high-Tc superconductors are of major importance for technological applications. For example, a high irreversibility magnetic field is a more desirable quality for a superconductor. The irreversibility line in the H�T plane is constituted by experimental points, which divides the irreversible and reversible behaviour of the magnetization. The irreversibility lines for series of Lu3-xGaxBa5Cu8Oy (x=0,1.2, 1.5 y 3) polycrystalline samples with different doping were investigated. The samples were synthesized using the usual solid estate reaction method. Rietveld-type refinement of x-ray diffraction patterns permitted to determine the crystallization of material in a tetragonal structure. Curves of magnetization ZFC�FC for the system Lu3-xGaxBa5Cu8Oy, were measured in magnetic fields of the 10�20,000 Oe, and allowed to obtain the values for the irreversibility and critical temperatures. The data of irreversibility temperature allowed demarcating the irreversibility line, Tirr (H). The obtained results allow concluding that in the system Lu3-xGaxBa5Cu8Oy presented a characteristic bend of the Almeida� Thouless (AT) tendency dominant for low fields and a bend Gabay�Toulouse (GT) behavior for high magnetic fields. This feature of the irreversibility line has been reported as a characteristic of granular superconductors and it corroborates the topological effects of vortexes mentioned by several authors.

Biography :

Email: carlos.parra@uptc.edu.co