PREPARATION OF SUBMICRON SIZE GAMMA-LITHIUM-ALUMINATE PARTICLES FROM THE MIXTURE OF ALUMINA SOL AND LITHIUM SALT BY ULTRASONIC SPRAY-PYROLYSIS

Gamma lithium aluminate particles of submicron size were directly prep ared by ultrasonic spray pyrolysis from two different solutions. One w as a colloidal mixture of alumina sol and lithium salt (S1), and the o ther was an aqueous solution of aluminum nitrate and lithium salt (S2) . The influence of these two different types of solution on the purity of the crystalline phase and the morphology of the particles was inve stigated, The pure gamma lithium aluminate particles were prepared at 800 degrees C from the colloidal solution (S1) which was obtained from aluminum isopropoxide and lithium formate. The particles prepared fro m the colloidal solution (S1) had purer gamma phase than that of the p articles prepared from the aqueous solution of aluminum nitrate and li thium salts (S2). The particles prepared from the aqueous solution of aluminum nitrate and lithium salt (S2) had smooth surfaces and low sur face area (7 m(2)/g), whereas the particles prepared from the colloida l solution (S1) had rough surfaces and high surface area (45 m(2)/g). (C) 1996 Academic Press, Inc.