Sol-gel synthesis of Na+ beta-Al2O3 powders

Powders of general formula Na1+xAl11O17+x/2 with x 0, 0.2 and 0.57 have been obtained by hydrolysis and condensation of metal alkoxides. X-ray diffraction investigations showed the crystallization of beta-alumina peaks at 1100 degreesC, confirmed by DTA/TG measurements. The same phase was revealed for pellets sintered in air at 1400 degreesC. Densities up to 97% of the theoretical value were reached. Electrical performances of pellets of x=0.2 and 0.57 compositions were investigated by Dielectric Analyzer (DEA) at various frequencies. The measured values confirmed the good conductivity and activation energy performances of the material. (C) 2003 Elsevier Ltd. All rights reserved.