Moisture resistance of Nd1+Ba2−Cu3O -based ceramics

Autor: K. Iguchi, Y. Hiroshima, R. Komatsu, Tomoichiro Okamoto, H. Nagata
Rok vydání: 2021
Předmět:
Zdroj: Ceramics International. 47:33577-33583
ISSN: 0272-8842
DOI: 10.1016/j.ceramint.2021.08.267
Popis: The moisture resistance of 5 mol% Nd2BaCuO5-added Nd1+xBa2−xCu3Oy (x = 0–0.8) ceramics was investigated. The samples were prepared by a solid-state reaction at 980 °C and exposed to a humid atmosphere at 40 °C and 93 %RH. The microstructure observation and X-ray diffraction measurement of the exposed samples revealed that the surface morphology and the crystal structure tended to be more stable when the amount of x was increased. The crystal structure was orthorhombic for x = 0 and tetragonal for x = 0.2–0.8. By comparing the lattice constants calculated by the bond valence to those determined by X-ray diffraction, it was suggested that a gap around the Ba site increased with the increasing x. The gap around the substituted Nd3+ for Ba2+ was considered to act as a trap site for OH−.
Databáze: OpenAIRE