INFLUENCE OF INDIUM AND TANTALUM AS AN IMPURITY ON THE NORMAL AND SUPERCONDUCTING STATE PROPERTIES OF IN-SITU PREPARED CU-NB COMPOSITE WIRES

The influence of impurities on the normal and superconducting state pr operties of Cu-Nb composite wires prepared by in situ technique have b een studied. The results show an increase in the normal state resistiv ity, resistivity ratio, critical current density and upper critical fi eld - important parameters for device application of superconducting c omposite wires with the addition of indium and tantalum impurities. Th ere is, however, a decrease in the transition temperature and the tran sition width of the wires.