The Rapid Formation of La(OH)3 from La2O3 Powders on Exposureto Water Vapor

The reactivity of various lanthana powders in air was studied. The materials rapidly hydroxylate to form a stable hydroxide, La(OH)3, at room temperature. Smaller amounts of an oxycarbonate species (La2O2CO3) are also observed following air exposure. This oxycarbonate phase is stable to hydroxylatio...

Full description

Saved in:
Bibliographic Details
Published inJournal of the American Ceramic Society Vol. 93; no. 4; pp. 1187 - 1194
Main Authors Fleming, Peter, Farrell, Richard A., Holmes, Justin D., Morris, Michael A.
Format Journal Article
LanguageEnglish
Published Malden, USA Blackwell Publishing Inc 01.04.2010
Online AccessGet full text

Cover

More Information
Summary:The reactivity of various lanthana powders in air was studied. The materials rapidly hydroxylate to form a stable hydroxide, La(OH)3, at room temperature. Smaller amounts of an oxycarbonate species (La2O2CO3) are also observed following air exposure. This oxycarbonate phase is stable to hydroxylation. All oxide materials synthesized here show rapid reactions so that 24 h of exposure to atmosphere is generally sufficient to cause complete hydroxylation at room temperature. The rate of reaction was related to the crystallite size as determined by XRD. The reaction was found to follow a two‐stage kinetic process, a relatively slow surface reaction followed by a rapid bulk reaction. The relevance of the reactivity of these powders is discussed.
Bibliography:ArticleID:JACE03564
ark:/67375/WNG-JSJTCVC5-8
istex:32D297A1CFA8C703A1C0473C03D10291592AF4F9
A. Krell—contributing editor
ObjectType-Article-2
SourceType-Scholarly Journals-1
ObjectType-Feature-1
content type line 23
ISSN:0002-7820
1551-2916
DOI:10.1111/j.1551-2916.2009.03564.x