Formation of the High-Tc Phase of the Superconducting Bi-Pb-Sr-Ca-Cu-O Thin Film by the Laser Ablation Method

Films of the Bi-Sr-Ca-Cu-O and the Bi-Pb-Sr-Ca-Cu-O superconductors have been synthesized by a laser ablation method. Pb doping decreases the melting temperature, making the formation of the high-T c phase much easier. The properties and structures of these thin films are mainly controlled by the thermal treatment and the composition of the targets for ablation. By controlling these conditions, as much as 40% of the total volume of the high-T c phase is obtained. A precursor state of the 80 K phase can be obtained even at 400°C by this laser ablation method.