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Protonated β″-aluminas, correlation of ion-exchange rates, chemical composition and resulting lattice constants

✍ Scribed by Günter Wilhelm Schäfer; Hyung Jun Kim; Fritz Aldinger


Publisher
Elsevier Science
Year
1997
Tongue
English
Weight
296 KB
Volume
97
Category
Article
ISSN
0167-2738

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✦ Synopsis


Powders within the K-b0-alumina phase field were prepared. Their chemical composition and lattice constants were characterized by X-ray diffraction (XRD) and chemical analysis. Powders of so-called NH / H O-b0-aluminas and 4 3

proton-b0-aluminas were made by ion-exchange and characterized by XRD and X-ray fluorescence analysis. For both sets of powder samples lattice constants were determined. Lattice constants of NH / H O-b0-aluminas still differ too much for 4 3 direct polycrystal preparation. Proton-b0-aluminas exhibit two minima. An area is described, where the conditions for a stress free ion-exchange are fulfilled thus allowing the preparation of polycrystals without cracking. The phase field ranges from 80-82 mol% Al O , 3-5 mol% MgO, and complementing K O.