Resistive transition measurements were reported for MgB2 strands with SiC dopants. The starting Mg powders were 325 mesh 99.9% pure, and the B powders were amorphous, 99.9% pure, and with a typical size of 1–2µm. The SiC was added, as 10mol% of SiC, to 90mol% of binary MgB2 [(MgB2)0.9(SiC)0.1]. Three different SiC powders were used, and the average particle sizes were 200nm, 30nm and 15nm. The strands were heat-treated for times ranging from 5 to 30min at 675 to 900C. Strands with 200nm-sized SiC additions had µ0Hirr and BC2 values which were maximum at 25.4T and 29.7T after heating (800C, 0.5h). The highest values were seen for strands with 15nm SiC heated at 725C for 0.5h. This had a µ0Hirr value of 29T and BC2 higher than 33T.

Large Upper Critical Field and Irreversibility Field in MgB2 Wires with SiC Additions. M.D.Sumption, M.Bhatia, M.Rindfleisch, M.Tomsic, S.Soltanian, S.X.Dou, E.W.Collings: Applied Physics Letters, 2005, 86[9], 092507 (3pp)