The appearance of 45° grain boundaries in c-axis oriented YBa2Cu3Ox films grown by pulsed laser deposition on MgO (001) substrates is discussed. X-ray φ-scan (in-plane orientation) measurements have revealed that YBa2Cu3Ox films grown at around 700°C have two types of grains with Mgo ∥ YBCO and MgO ∥ YBCO in-plane epitaxial relationships. A plausible growth model is proposed from the viewpoints of lattice matching and ionic adhesive energy. The ratio of 0° and 45° grains is found to be a function of the substrate temperature. By decreasing the substrate temperature, we obtained c-axis oriented YBa2Cu3Ox thin films with only a Mgo ∥ YBCO in-plane epitaxial relation. We have eliminated the 45° grain boundaries which drastically increase the surface resistance of the YBa2Cu3Ox films for microwave applications.
|Number of pages||4|
|Journal||Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers|
|Issue number||4 A|
|Publication status||Published - Dec 1 1999|
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)