Lanthanum and calcium doped YBa2Cu3Oy films grown at low temperature and pressure

✍ Scribed by H.M. Appelboom; H. Sato; M. Naito

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 848 KB
• Volume: 221
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(94)90674-2

✦ Synopsis

We have fabricated lanthanum and calcium doped YBa2Cu3Oy films with co-evaporation at low oxygen/ozone pressures according to the stoichiometric formulae YLaxBa2_xCu3Oy and Yl _xCaxBa2Cu3Oy. The lanthanum doped films show a strong reduction or absence of solid solubility of lanthanum on the barium site compared to bulk material made at atmospheric oxygen pressure, analogous to what has been reported previously for Sml +xBa2_xCu3Oy films [ Physica C 214 (1993 ) 323 ]. In the calcium doped films we find a solid solubility limit which is apparently similar to that reported for bulk material synthesized at atmospheric oxygen pressure. The reduction of solid solubility in the YLaxBa2_~Cu3Oy system is explained by a shift of the low oxygen pressure decomposition line to higher pressure with lanthanum doping. We also report here on the successful synthesis of oxygen-deficient superconducting Y~_xCa~Ba2Cu306 films.