Microstructure and superconductivity of La1.85Sr0.15CuO4 nanowire arrays

摘要

Superconducting La1.85Sr0.15CuO4 nanowire arrays are successfully synthesized through a sol-gel method combined with porous alumina as a morphology-directing hard template for the first time. The morphology, structure, and composition of the as-prepared nanowire arrays are characterized by field-emission scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. These experimental results indicate that the nanowires are well crystallized with an approximately uniform diameter of about 30 mn. The superconducting transition temperature T-c (ca. 30 K) of the annealed nanowires is lower than that in bulk La1.85Sr0.15CuO4. It is suggested that this superconductivity suppression is derived from the weakening of in-plane hybridization in the nanowire system.