Preparation of metastable Bi-2223 phase of Bi2(LnxCa2−x)Ca2Cu3Oz thin films (0.3⩽x⩽0.7, Ln=Pr, Nd, Sm, Eu and Gd)

Preparation of Bi2(LnxCa2−x)Ca2Cu3Oz thin films (0.3⩽x⩽0.7, Ln=Pr, Nd, Sm, Eu and Gd) by the laser ablation method and their physical properties are described. These films have been of a metastable Bi-2223 phase, which had not been synthesized by the solid-state reaction method. In the Bi2(PrxCa2−x)Ca2Cu3Oz system, the resistivity of Bi-2223 films has decreased with decreasing Pr content x, and the film with x=0.3 has shown the lowest resistivity. When x is fixed to 0.3 in the Bi2(LnxCa2−x)Ca2Cu3Oz systems, the film with Ln=Sm has shown the lowest resistivity. However, the result of the resistivity and magnetic measurements have shown that none of the films is superconductive.