Synthesis and characterization of electrospun superconducting (La, Sr)CuO₄ nanowires and nanoribbons

Superconducting nanowires, fabricated by various methods, represent an important family of nanostructures. The dimensions of the nanowires are typically about 10-200 nmin diameter, and the length varies from some ìmup to themmrange, depending on the chosen fabrication method. By means of electrospinning, we have prepared nanowires of (La,Sr)CuO₄. The electrospinning technique enables the growth of long nanowires up to the millimeter range, while the diameter can be controlled by the processing parameters. When analyzing the samples by means of scanning electron microscopy, we found that there are two types of nanoobjects formed: While the majority of the material consists of nanowires, there are also nanoribbons formed, which are very thin and, as a consequence, also transparent. SEM/TEManalysis has shown that these nanoribbons are about two unit cells thick. In this contribution, we present a thorough microstructural characterization of these nanowires including SEM and TEM, and explore the formation of the different nanoobjects. Further, we discuss the possibilities for employing these nanowires as building blocks for new nanoporous bulk superconducting materials.