Superconductor YBa2Cu3-xNixO7-delta compounds prepared by electrospinning

Abstract: This work describes the synthesis and characterization of YBa2Cu3-xNixO7-delta (0.00 <= x <= 0.04) compounds prepared by an electrospinning technique. Stoichiometric solutions of Y-Ba-Cu-Ni were used to electrospin nanowires of these compounds, which were dried and heat-treated at temperatures ranging from 350 degrees C to 925 degrees C in an oxygen atmosphere. All samples were characterized by x-ray diffraction (XRD), scanning electron microscopy, and temperature magnetization curves. As prepared and dried at 100 degrees C, these samples present a nanowire shape with a smooth surface, with external diameters of similar to 600 nm and a large length (>10 mu m). After the heat treatment at 780 degrees C, all of them maintain their nanowire morphology with a rough surface with external diameters of similar to 600 nm and length values ranging from 5 to 10 mu m. All samples crystallize into the perovskite structure with orthorhombic symmetry (Pmmm space group). The most intense Bragg reflections arise from the YBa2Cu3-xNixO7-delta phase and low-intensity peaks of additional phases. The temperature dependence of magnetization of these nanowires reveals a diamagnetic transition at temperatures close to the critical temperature, T-c, which is related to the superconductor transition in these compounds. The T(c )values range between 70 and 93.2 K for samples with x = 0.04 to x = 0.00, respectively, where the substitution of Cu with Ni results in a lower T-c.

Author(s): Bernard, JC; Modesto, DA; Medina, MS; Zenatti, A; Venancio, EC; Leite, ER; Lanfredi, AJC; Escote, MT

MATERIALS RESEARCH EXPRESS

DOI: 10.1088/2053-1591/ab1fa3