Lithium-stabilized beta-double-prime-alumina production, for solid electrolytes and nitrogen oxide sensors and selective membranes, comprises direct reaction sintering of aluminates and gamma-alumina

摘要

Lithium-stabilized metal beta-double-prime-alumina ceramic production comprises firing a mixture of the metal aluminate with lithium aluminate and psi -alumina. A lithium-stabilized Me- beta -Al2O3 ceramic is produced by firing a mixture of a lithium aluminate (Li2O.Al2O3), a metal aluminate (Me2O.Al2O3) and psi -Al2O3, where Me = sodium, potassium, rubidium, cesium, copper, lithium, silver or tantalum. Preferred Features: The starting materials are mixed in a stoichiometric ratio and, prior to sintering, are formed to: (a) a molded body by molding and/or pressing or injection molding; (b) a 1-100 mu m thick layer by screen printing; or (c) a 20 mu m to 2 mm thick foil by a foil drawing technique. After sintering, the product may be ion exchanged with nitrosyl cations to obtain a lithium-stabilized NO+- beta -Al2O3 ceramic.