  The paper reports the first successful fabrication of MgB2 superconducting
tape using a flexible metallic substrate as well as its strong pinning force,
which was verified by direct measurement of transport critical current density.
The tape was prepared by depositing MgB2 film on a Hastelloy tape buffered with
an YSZ layer. The Jc of the tape exceeds 105A/cm2 at 4.2K and 10T, which is
considered as a common benchmark for magnet application. The Jc dependence on
magnetic field remains surprisingly very small up to 10T, suggesting that the
tape has much better magnetic field characteristic than conventional Nb-Ti
wires in liquid helium.
