Issue 9, 2002

Study of fluorite phases in the system Bi2O3–Nb2O5–Ta2O5. Synthesis by mechanochemical activation assisted methods

Abstract

Mechanochemical activation followed by annealing at moderate temperatures results in the stabilisation, at room temperature, of different fluorite-type phases, belonging to the Bi2O3–Nb2O5, Bi2O3–Ta2O5 and Bi2O3–Nb2O5–Ta2O5 systems. The results obtained from different starting compositions and mechanical activation devices (vibrating and planetary ball mills) were compared with those obtained by classical solid-state synthesis methods. Vibrating ball mill activation yields amorphous precursors, which permits one to obtain fluorites with increasing pentavalent cation content when the annealing temperature is further increased. Planetary ball milling leads to the apparent mechanosynthesis of a fluorite phase at room temperature. The products were studied by X-ray powder diffraction at room temperature and above, thermal analysis techniques and transmission electron microscopy. Moreover, impedance spectroscopy measurements carried out on Bi3MO7 (M = Nb, Ta) fluorites, obtained by a mechanochemically assisted method, showed that these materials are good ionic conductors, with conductivities at 600 °C of 5 × 10−4 S cm−1 or higher, the processing history of the materials having a great influence on their properties.

Graphical abstract: Study of fluorite phases in the system Bi2O3–Nb2O5–Ta2O5. Synthesis by mechanochemical activation assisted methods

Article information

Article type
Paper
Submitted
19 Apr 2002
Accepted
17 Jun 2002
First published
30 Jul 2002

J. Mater. Chem., 2002,12, 2774-2780

Study of fluorite phases in the system Bi2O3–Nb2O5–Ta2O5. Synthesis by mechanochemical activation assisted methods

A. Castro and D. Palem, J. Mater. Chem., 2002, 12, 2774 DOI: 10.1039/B203857A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Spotlight

Advertisements