Micro-Raman scattering in Nb2O5–TiO2 ceramics

✍ Scribed by P. S. Dobal; A. Dixit; R. S. Katiyar; H. Choosuwan; R. Guo; A. S. Bhalla

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 118 KB
• Volume: 33
• Category: Article
• ISSN: 0377-0486
• DOI: 10.1002/jrs.828

✦ Synopsis

Abstract

Single‐phase (Nb~2~O~5~)~1−x~(TiO~2~)~x~ ceramics were prepared for x = 0.00, 0.05, 0.08 and 0.11 compositions using a solid‐state reaction technique. The effect of TiO~2~ substitution on the vibrational and phase transition behavior of Nb~2~O~5~ was studied using the micro‐Raman scattering technique and compared with similar results on Ta~2~O~5~. The external modes resulting from interaction among various polyhedra were observed and vibrational changes were studied in the temperature range −200 to 1100°C. An increase in structural disorder was reflected in the Raman spectra with increasing TiO~2~ content in both Nb~2~O~5~ and Ta~2~O~5~. Ta~2~O~5~ shows a phase transition at about 300°C . However, a low‐temperature phase transition was observed about 50°C from (Nb~2~O~5~)~1−x~(TiO~2~)~x~ compositions. Copyright © 2002 John Wiley & Sons, Ltd.