THE EFFECT OF ELECTRON IRRADIATION ON TRANSITION TEMPERATURE AND MECHANICAL PROPERTIES OF NANOSIZE MgO ADDED Bi2Sr2CaCu2O8(Bi-2212) SUPERCONDUCTOR CERAMICS

Abstract

Bi₂Sr₂CaCu2O₈ (Bi-2212) bulk samples with addition of 3% and 5% weight percentage of nanosize MgO particles were prepared by using the conventional solid-state reaction method. Oxide and carbonate powders were used in the preparation of samples. In solidification process, MgO substrate plays a major role in constructing the alignment and growth of Bi-2212 phase. The superconducting properties of the samples change significantly with different amount of MgO addition. It was found that the addition altered the transition temperature, T_C and the strength of the samples without affecting its Bi-2212 phase structure. Microstructural analysis indicates that a small amount of Bi-2212 is decomposed into Cu2O and other impurity phases while a significant amount of un-reacted Bi-2212 particles embedded into MgO matrix, and believed to be acted as effective pinning centers for vortices. The nanosize MgO samples were also irradiated with small dose of electron irradiation 40 kGray and 80 kGray, respectively. For the irradiated samples, the microstructure was found to be more textured and thus enhanced the strength of the samples. These enhanced properties indicate that irradiated nanosize MgO added Bi-2212 superconductor ceramics have potential for applications in robust environment.