Preparation of TlBaCaCuO Films by Annealing DC-Sputtered BaCaCuO Films in Thallium Oxide Vapours

Abstract

Superconducting Tl BaCaCuO films are prepared from Tl-free precursor films and thallium-oxide vapours by an ex situ high-temperature annealing. The BaCaCuO films are deposited by high-rate sputtering from a metallic alloy target for the first time. The superconducting properties of the films on various substrates are investigated in dependence on sputter and annealing conditions. The annealed films are highly oriented with the c-axis perpendicular to the film surface and have critical temperatures Tc0 (R = 0) up to 114 K and critical current densities up to 4 × 104 A/cm2 at 77 K.