Superconducting Properties and Workability of Stainless Steel/Iron Sheathed MgB(2) Thin Wires

MgB(2) superconducting thin wires sheathed with stainless steel (SS) and pure iron (Fe) have been prepared by in-situ powder-in-tube process. Using Magnesium hydride MgH(2) and amorphous B powders with and without SiC nano-sized powder addition, SS/Fe/MgB(2) composites have been fabricated through grooved rolling and drawing to form the round wires of 0.53~ 0.10 mm in diameter. Both SS and Fe sheaths were hardened to be a Vickers hardness of around Hv 650 and Hv 510 through cold-working at room temperature. The transport critical current (I(c)) at 4.2 K for the MgB(2) wire increases with decreasing the amount of SiC addition in lower magnetic field than 1 T. The I(c) at 4.2 K and self-field for the MgB(2) wire of 0.10 mm in diameter without SiC addition is 14 A, which corresponds to the critical current density (J(c)) of around 1 x 10(4) A/mm(2). The present MgB(2) thin wires are promising as current leads and level sensor for liquid hydrogen.