An All Sol-Gel Process for the Heteroepitaxial Growth of YBa2Cu3O7−x/LaNiO3/YBa2Cu3O7−x Tri-layer

Abstract

Abstract:The preparation of a YBa 2 Cu 3 O 7−x /LaNiO 3 /YBa 2 Cu 3 O 7−x sandwich structured film on a LaAlO 3 (100) substrate by a sol-gel method was investigated. YBa 2 Cu 3 O 7−x /LaNiO 3 /YBa 2 Cu 3 O 7−x tri-layer heterostructures with different epitaxial characteristics can be deposited by controlling the heat treatment temperature. X-ray diffraction and transmission electron microscopy results show that the bottom YBCO film grows epitaxially on the LaAlO 3 substrate along the c axis, and that this epitaxial growth trend is extended to the subsequently deposited LaNiO 3 film. For this reason, the LaNiO 3 film also grows epitaxially along the c axis. Furthermore, this epitaxial growth trend is extended to the top YBa 2 Cu 3 O 7−x film, yielding YBa 2 Cu 3 O 7−x /LaNiO 3 /YBa 2 Cu 3 O 7−x tri-layer heterostructures with epitaxial growth characteristics along the c axis, which enables both the bottom and top YBa 2 Cu 3 O 7−x layers to possess superconducting abilities.