Thallium group superconducting wire
In order to provide a crystal oriented high quality thallium group superconducting wire having a high critical current density, thallium group superconducting film is formed on oxide single crystal fiber having plane facets and polygonal cross section in the thallium group superconducting wire, wherein c-axis of the thallium group superconducting film is oriented perpendicularly, and a- and b-axis are oriented in parallel to the longitudinal direction of the above fiber, respectively, and resulting to obtain a high quality thallium group superconducting wire with Jc of 105 A/cm2 or more at 77K.