X-ray Structure Refinements and Strain Analysis of Substituted Cubic Lead Pyrochlores Pb2(M2−yPby)O7−δ(0.0<y<0.8; M=Nb or Ta)

✍ Scribed by G. Nalini; R. Somashekar; T.N. Guru Row

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 204 KB
• Volume: 156
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.2000.8983

✦ Synopsis

6.57

(3) belonging to this family, are re5ned in the cubic space group Fd3 m (Z ‫؍‬ 8; lattice parameter a ‫؍‬ 10.762(1), 10.744(1), 10.757(5) A s , respectively) using the Rietveld re5nement approach. The analyses suggest that the B-site is partially occupied by Pb leading to the general formula Pb 2 (M 2؊y Pb y )O 7؊ (0.0 < y < 0.8; M ‫؍‬ Nb or Ta). There is an overall broadening observed in the X-ray peak widths in 1, 2, and 3 compared to the Pb-de5cient parent phases. It is observed that the X-ray peak widths of 2 is broad, while 3 displays narrow peak widths. It is found via strain analysis that the line broadening observed correlates with the strain in the lattice. 2001 Academic Press