Abstract
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.
| Original language | English |
|---|---|
| Pages (from-to) | 121-125 |
| Number of pages | 5 |
| Journal | Physica C: Superconductivity and its Applications |
| Volume | 338 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 1 Aug 2000 |
| MoE publication type | A4 Article in a conference publication |
| Event | 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 Duration: 15 Oct 1999 → 16 Oct 1999 |
Funding
Dr. S.R. Lee is acknowledged for useful advice during the course of this work. One of the authors (J.L.) acknowledges the kind support from the Japan Society for the Promotion of Science. The present work has been supported by a Grant-in-Aid for Scientific Research (contract No. 11305002) from The Ministry of Education, Science and Culture of Japan, and also by an International Collaborative Research Project Grant-1999 of the Materials and Structures Laboratory, Tokyo Institute of Technology.