Perovskite Structures in the Formation of Nano−rods in REBa₂Cu₃O_7-δ Films

Self-organization to perovskite structures

Abstract

Cubic perovskite structure has been found to play an important role for the nano-rod formation in REBa₂Cu₃O_7-δ films. BaWO₄,with a sheelite structure, and BaNb₂O₆, with a tungsten bronze structure, were doped into REBa₂Cu₃O_7-δ targets. Laser-deposited, these materials formnano-rods in REBa₂Cu₃O_7-δ films accompanied by Ln elements, resulting in the composition of a pseudo-cubic perovskite structure. This was confirmed by selected area electron diffraction patterns (SADP) and composition mapping using energy-dispersive X-ray spectroscopy scanning transmission electron microscope (EDS-STEM) analysis. BaWO₄ with a sheelite structure, and BaNb₂O₆ with a tungsten bronze structure, doped into targets no longer retain their structures, but canform pseudo-cubic perovskite structures in laser-deposited REBa₂Cu₃O_7-δ films. The perovskite crystal structure is thought to beimportant for nano-rod formation in the laser deposited REBa₂Cu₃O_7-δ film.