| abstract |
This invention relates to a process for the preparation of a crystalline compound having the empirical formula LaCrxA1-xO4.yH2O in which A represents a metal selected from the group consisting of Mg, Sr, Ca and Ba, x is between 0.99 and 0 , About 7 and is between 0 and 0.15. The process involves adding a solution of the appropriate metal salts to an ammonium hydroxide solution, thereby precipitating an intermediate from a hydroxide gel which is dried and calcined in air to produce the resulting crystalline compound which has a huttonite structure . Furthermore, this invention relates to a method for preparing a ceramic powder having the empirical formula LaCrxA1-xO3, in which A represents a metal selected from the group comprising Mg, Sr, Ca and Ba, and x is between 0.99 and about 0.7. Finally, a ceramic composition having the empirical formula LaCrxA1-xO4.yH2O having a huttonite structure is also described. |