Flux pinning due to MgO particle additions in partial-melting processed Bi-2212 bulk

• Published in: IEEE transactions on applied superconductivity 1999, Vol.9 (2), p.2347-2350
• Main Authors: BAORONG NI, TOMISHIGE, Y, JIWU XIONG, ZHAO, Z
• Format: Article
• Language: English
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Microelectronic fabrication (materials and surfaces technology); Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Superconducting devices
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/77.784942

In order to introduce effective pinning centers into Bi-2212 superconducting bulk, the addition of small MgO particles to Bi-2212 bulk and its effect on flux pinning were studied. Bi-2212 bulk samples were prepared by employing a normal partial-melting process, with a 0-8 vol.% of MgO particles addition. The morphology of Bi-2212 with MgO doping was investigated by means of XRD and EPMA. The magnetization and critical current densities (J sub(c)'s) in various magnetic fields and temperatures were measured by using a SQUID magnetometer. It was found that J sub(c) in samples with relatively large MgO particles introduced shows a larger value than that in MgO-free sample, which implies that the MgO particles act as effective pinning centers and enhance the flux pinning characteristic in Bi-2212 bulk. A qualitative agreement between the experimental results and theoretical estimation was obtained.