Axiotaxy in oxide heterostructures: Preferential orientation of BaCeO3 nanoparticles embedded in superconducting YBa2Cu3O7 −δ thin films

Abstract

Addressing and controlling texture in crystalline materials is an extremely important issue, since this can largely influence and finally control the materials properties, be it mechanical, electrical, magnetic, etc. In this work, we present an axiotaxial orientation of nanoparticles embedded in an epitaxial oxide heterostructure, signaling the importance of texture studies on nanocomposite thin films. Synchrotron X-ray diffraction studies revealed that embedded BaCeO3 (BCO) nanoparticles within the YBa2Cu3O7−δ (YBCO) superconductor prepared from chemical solutions presented an axiotaxial texture. Incorporated nanostructured defects such as BCO within a YBCO matrix are relevant for the fabrication of enhanced superconducting materials and devices. The YBCO presented the main out-of-plane epitaxial growth and two in-plane secondary orientations, which defined the three distinct axiotaxial axis of rotation of the BCO nanoparticles. In addition, some incorporated BCO grains showed an epitaxial growth orientation produced by a double-axiotaxy, i.e. the BCO nanoparticles exhibit a preferential orientation with respect to two distinct YBCO grains, limiting their rotational freedom. Texture studies like the ones shown here are thus a must to investigate and enhance the effect of the embedded grains on the final properties of the hybrid superconducting thin films.