Effect of aromatic hydrocarbon addition on in situ powder-in-tube processed MgB2 tapes

We fabricated in situ powder-in-tube processed MgB2/Fe tapes using the aromatic hydrocarbons benzene, naphthalene, and thiophene as additives, and investigated the superconducting properties. We found that these aromatic hydrocarbons were very effective for increasing the Jc values. The Jc values of 20 mol% benzene-added tapes reached 130 A mm−2 at 4.2 K and 10 T. This value was almost comparable to that of 10 mol% SiC-added tapes and about four times higher than that of tapes with no additions. Microstructural analyses suggest that this Jc enhancement is due to both the substitution of carbon for boron in MgB2 and the smaller MgB2 grain size.