Effect of thermal history on the transport properties and the location of Fe in YBa2Cu3O7 thin films
Abstract
Epitaxial Fe-substituted YBa2Cu3O7 films on LaAlO3 substrates prepared by pulsed-laser deposition exhibit a large variation in Tc with changes in the cooldown rate of the films in an O2 environment immediately after deposition. A rapid cooldown rate (200 °C/min) yields surprisingly high-Tc films with Tc≳75 K for 13% of the Cu replaced by Fe, while a slow cooldown of 10 °C/min results in low-Tc films with Tc→0 at 11% Fe, a greater suppression than reported for bulk materials. In addition, post-deposition anneals in O2 affect Tc significantly, even for anneal temperatures as low as 370 °C. These results are interpreted in terms of isolated- and clustered-Fe atoms substituted on the Cu chains sites.
- Publication:
-
Applied Physics Letters
- Pub Date:
- June 1992
- DOI:
- 10.1063/1.106777
- Bibcode:
- 1992ApPhL..60.3042B
- Keywords:
-
- Copper Oxides;
- High Temperature Superconductors;
- Iron;
- Superconducting Films;
- Transport Properties;
- Yttrium Oxides;
- Crystal Structure;
- Lanthanum Compounds;
- Mixed Oxides;
- Thin Films;
- Transition Temperature;
- Solid-State Physics