THE EFFECT OF FLUORINE ON THE PHASE-FORMATION AND PROPERTIES OF TL-BASED SUPERCONDUCTORS

Fluorine was found to affect the phase formation and superconducting p roperties of Tl-based superconductors. By varying x in (Tl0.5Pb0.5)Sr1 .6Ba0.4Ca2Cu3OyFx, synthesized superconductors, an increase was found in the transition temperature and critical current density. These impr ovements in the superconducting properties are discussed in terms of p artial substitution of fluorine into the oxygen sites which in turn af fects the hole doping in this material. Structure, microstructure and elemental analysis by XRD, SEM and EDX techniques are reported; the la tter of which shows the fluorine distribution.