New Hydrotalcite-like Compounds Containing Yttrium

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• 作者：J. M. Fern&aacute ; ndez ; C. Barriga ; M. A. Ulibarri ; F. M. Labajos ; and V. Rives
• 刊名：Chemistry of Materials
• 出版年：1997
• 出版时间：January 1997
• 年：1997
• 卷：9
• 期：1
• 页码：312 - 318
• 全文大小：279K
• 年卷期：v.9,no.1(January 1997)
• ISSN：1520-5002

文摘

Layered double hydroxides (LDHs) containing Mg²⁺,Al³⁺, and Y³⁺ in the brucite-likelayersand with carbonate as counteranion have been prepared following thecoprecipitation methodat constant pH. The Al/Y ratio depends on the concentrations inthe starting solutions.The crystallinity of the layered materials decreases as the Al/Yratio increases, probablydue to the distortions introduced by the large difference in the ionicradii of the cations. Oncalcination at 750 ages/entities/deg.gif">C MgO (probably containing Al³⁺cations) and Y₂O₃ are formed fromthesample richest in Y, while the other samples lead to formation of MgOand presumablyAl₂Y₄O₉. At 1000 ages/entities/deg.gif">C, MgO,MgAl₂O₄, andAl₂Y₄O₉ are formed in all cases.Exposure ofsamples calcined at 750 ages/entities/deg.gif">C in air at room temperature leads toreconstruction of a Mg,Alhydrotalcite and segregation of Y-containing phases.