Methods of introduction of MgO nanoparticles into Bi-2212/Ag tapes

• Published in: Physica. C, Superconductivity Superconductivity, 2006-02, Vol.434 (1), p.115-120
• Main Authors: Agranovski, Igor E., Ilyushechkin, Alexander Y., Altman, Igor S., Bostrom, Thor E., Choi, Mansoo
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Flux pinning centers; Granular, melt-textured, amorphous and composite superconductors; High-temperature superconductor; Inhomogeneous superconductors and superconducting systems; MgO nanoparticle doping; Physics; Superconductivity
• ISSN: 0921-4534; 1873-2143
• DOI: 10.1016/j.physc.2005.12.005

The effect of addition of ultra-fine MgO particles, obtained by Mg combustion, in Bi-2212/Ag tapes was investigated. Bi-2212/Ag tapes were prepared by coating and partial melt processing. Four different methods of MgO particles embedment were applied in green tape preparation; settlement of MgO in Bi-2212, pre-mixing of MgO in the solvent, deposition of the MgO into the solvent, and deposition of MgO onto the surface of Bi-2212. Microstructural studies of processed tapes show that uniformity of MgO particles distribution in Bi-2212 matrix depends on the methods of tape preparation. MgO particles, introduced in Bi-2212 matrix by all applied methods, significantly enhanced transport properties of the tapes. The Jc degradation with the increase of magnetic field and/or temperature in all doped samples was significantly lower compared to un-doped Bi-2212 samples. The best improvement was achieved when MgO particles were introduced into Bi-2212 matrix by settlement method of the tape coating. The improvement also depends on a magnitude of the magnetic field and operating temperatures.