The Effect of Ru Substitution on the Thermal, Structural and Magnetic Properties of Bi3Sr2Ca2Cu3O (delta) Superconducting System


AKSAN M. A., YAKINCI M. C., KADOWAKI K.

JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM, cilt.23, sa.3, ss.371-380, 2010 (SCI-Expanded) identifier identifier

Özet

We have investigated the effect of Ru substitution on the thermal, structural/microstructural and magnetic properties of Bi-3223 system prepared using solid-state technique. The crystallization studies were made using DSC data with four different uniform heating rates. The formation temperature of Bi-2212 did not change significantly with increasing the Ru concentration; however, it was found that the thermal decomposition temperatures decreased. The activation energy for crystallization, E (a) , decreased by increasing the Ru concentration. X-ray diffraction and SEM measurements showed that substitution of Ru for Bi caused significant changes in the crystal structure of the BSCCO material. A distorted and multiphase crystalline structure was observed. The M--T measurement exhibited that superconducting onset temperature (T (c) ) decreased with increasing the Ru concentration in the system. The substitution of Ru for Bi caused the formation of ferromagnetic clusters in the materials, which destroyed the superconductivity in the system. Symmetric M(H) loops were obtained for lower Ru substitution, but in the case of high level substitution of Ru, a typical weak ferromagnetic-like hysteresis loop was found. It is believed that the Ru ions in the system are responsible for ferromagnetic behavior in the highly substituted materials.