Structural and electrical properties of lanthanum copper oxide epitaxial thin films with different domain morphologies

Abstract

Herein, we investigated the domain morphologies of defect-perovskite LaCuO_x (2.5 ≤ x ≤ 3.0) thin films grown on cubic SrTiO₃ (100) and orthorhombic NdGaO₃ (110) substrates by pulsed-laser deposition. Both films were composed of narrow rectangular-shaped domains, which extended in the [001] direction of LaCuO_x. The LaCuO_x film grown on SrTiO₃ showed a labyrinth-like domain pattern composed of 90° domains, whereas the film on NdGaO₃ displayed a stripe pattern with 180° domains. Furthermore, we observed anisotropy in the resistivity; the resistivity along the length of the domains was about three times lower than that across their width. This indicated that the domain boundaries behaved as carrier scattering centers.