Superconducting Properties of Aromatic Hydrocarbon-Added Powder-in-Tube ${\rm MgB}_{2}/{\rm Fe}$ Tapes

We investigated the superconducting properties of aromatic hydrocarbon added
in situ
-processed powder-in-tube (PIT) MgB
₂
/Fe tapes. We used aromatic hydrocarbons such as benzene, naphthalene, thiophene, ethyltoluene, toluene and xylene. We found that these aromatic hydrocarbons were very effective for increasing the Jc values. X-ray diffraction analyses suggest that the substitution of carbon for boron occurred in these tapes. 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. The 10 mol% ethyltoluene-added tape showed a Jc of 390 at A/mm
²
4.2 K and 8 T. This value is higher than that of the 10 mol% SiC-added tape.