Oxygen-deficient BaSm(Cu0.5+xFe0.5-x)2O5+δ (x = -0.5, -0.45, -0.4, -0.1 and 0.0) double-perovskite samples have been successfully obtained by means of a novel synthesis technique utilizing an Fe/FeO getter encapsulated together with the starting material mixture in an evacuated silica-glass tube. The reducing conditions during the synthesis correspond to an oxygen partial pressure of approx. 7.6 × 10-16 atm. From X-ray diffraction (XRD), transmission electron micrographs (TEM) and energy-dispersive X-ray (EDX) analyses, the samples have been confirmed to be of essentially single phase. By post-annealing the as-synthesized samples under O2 or H2/Ar mixed gas, the amount of excess oxygen was controlled. Approaching δ ≈ 0 required prolonged annealing periods under reducing conditions. Samples having -0.4 < x < -0.1 did not form as a single-phase material under the present synthesis conditions.
|Julkaisu||Physica C: Superconductivity and its Applications|
|DOI - pysyväislinkit|
|Tila||Julkaistu - 1 elok. 2000|
|OKM-julkaisutyyppi||A4 Artikkeli konferenssijulkaisuussa|
|Tapahtuma||International Discussion Meeting on Chemistry Approaches to High-Tc Superconductive Materials / 5th International Workshop on Chemical Designing and Processing of High-Tc Superconductors (Chem-HTSC-V) - Yokohama, Jpn|
Kesto: 15 lokak. 1999 → 16 lokak. 1999