SYNTHESIS OF THIN SUPERCONDUCTING HGBA2CACU2O6-ABLATED PRECURSORS(DELTA FILMS BY POSTANNEALING OF LASER)

Superconducting HgBa2CaCu2O6+delta (Hg-1212) thin films have been prep ared by laser ablation followed by post-annealing at high temperatures . Two synthesis methods were investigated, using (1) direct reaction o f Hg-Ba-Ca-Cu-O precursor films in a Hg-controlled ambience, and (2) t hermal diffusion of Hg into Ba-Ca-Cu-O precursor films in a controlled atmosphere containing both Hg-and Tl-bearing species. Effects of the annealing temperature, time, and bulk material composition on the Hg-1 212 film and residual impurities are presented. Surface morphologies, growth defects, and transport properties of Hg-1212 on SrTiO3 substrat es are discussed. Formation of Hg-1212 films on MgO and LaA1O(3) subst rates is briefly described.