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Synthesis and powder diffraction analysis of tri-rubidium penta-tantalum oxide, Rb3Ta5O14, with novel three-dimensionally nanostructured Rb-bearing channels

Published online by Cambridge University Press:  05 March 2012

A. Oono
Affiliation:
Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Nagatsuta, Midori, Yokohama 226-8502, Japan
M. Yashima
Affiliation:
Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Nagatsuta, Midori, Yokohama 226-8502, Japan
D. du Boulay
Affiliation:
Materials and Structures Laboratory, Tokyo Institute of Technology, Nagatsuta, Midori, Yokohama 226-8503, Japan
N. Ishizawa*
Affiliation:
Materials and Structures Laboratory, Tokyo Institute of Technology, Nagatsuta, Midori, Yokohama 226-8503, Japan
A. Saiki
Affiliation:
Center for Advanced Materials Analysis, Tokyo Institute of Technology, 2-12-1, Oookayama, Meguro, Tokyo 152-8550
S. Oishi
Affiliation:
Department of Environmental Science and Technology, Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553, Japan
*
a)Author to whom correspondence should be addressed. Electronic mail: [email protected]

Abstract

The powder pattern of Rb3Ta5O14 is reported here for the first time. Single crystals of Rb3Ta5O14 of 0.1–0.2 mm in size were grown using a RbCl flux at 1100 °C. The Rb3Ta5O14 powders were synthesized at 1200 °C by firing the Rb2CO3 and Ta2O5 raw materials with starting Rb/Ta ratios ranging from 0.450 to 0.800. The products with Rb/Ta ratios between 0.550 and 0.633 contained almost pure Rb3Ta5O14 with Rb/Ta ratio of 0.600, while those with Rb/Ta ratio larger than 0.677 also contained the α form of Rb4Ta6O17 with the Rb/Ta ratio of 0.677. Past studies of the synthesis and characterization of Rb4Ta6O17 should be carefully examined in the light of possible coexistence with Rb3Ta5O14, because the former structure has not been completely solved, and thus the powder pattern is inaccurate, while the presence of the latter had not been known until the present study.

Type
Technical Articles
Copyright
Copyright © Cambridge University Press 2003

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