Jayaraman, V and Periaswami, G and Kutty, TRN (2000) Preparation and characterization of rubidium-beta-alumina by the gel-to-crystallite conversion method. In: Materials Research Bulletin, 35 (8). 1213 -1225.
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Preparation of Rb-beta -alumina was realized by the gel-to-crystallite conversion method. Reaction of hydrated aluminum hydroxide gel with RbOH in ethanol medium gave rise to the Rb+-inserted pseudoboehmite precursor under wet chemical conditions. The thermal decomposition of the precursor yielded Rb-beta -alumina. The Rb2O:Al2O3 ratio of monophasic Rb-beta -alumina ranged from 1:10 to 1:22. The extended stability in the compositional range is due to the fact that the conduction planes containing Rb+ and O2- ions can have lower occupancy of Rb+ ions for larger sized alkali ions, permitting the steric separation of the adjoining spinel blocks. High-resolution electron microscopy revealed that the decreasing occupancy of alkali ions in the conduction plane is balanced by changing widths of spinel blocks arising from the shift of tetrahedral Al3+ ions to octahedral sites and an accompanying increase in stacking defects. (C) 2000 Elsevier Science Ltd. All rights reserved.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to Elsevier Science.|
|Keywords:||A.Oxides; B.Chemical synthesis; C.Electron microscopy; D. Defects.|
|Department/Centre:||Division of Chemical Sciences > Materials Research Centre|
|Date Deposited:||09 Sep 2010 12:12|
|Last Modified:||19 Sep 2010 06:16|
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