NEODYMIUM TITANATE AND BARIUM NEODYMIUM TITANATE PROCESSES FOR THEIR PREPARATION AND THETR APPLICATIONS IN CERAMIC COMPOSITIONS

摘要

A fine powder of neodymium titanate or barium neodymium titanate, a process for its preparation and applications in ceramic compositions. A suspension of particles is formed by mixing a solution of neodymium nitrate or a solution of barium and neodymium nitrates with a sol of titania having a pH of from about 0.8 to 2.5 which contains elementary crystallites of TiO2 having a size of from about 10 to about 100 ANGSTROM in diameter which are agglomerated into submicron masses of from about 200 to about 1,000 ANGSTROM in diameter. The suspension obtained is dried, and the dried product is calcined at a temperature between 800 DEG C. and 1,300 DEG C., preferably for about 1 to 24 hours. If necessary, the powder obtained is milled. The fine powder obtained has a low fritting temperature and its density after heating for 2 hours at 1,300 DEG C. is greater than or equal to 95% of the theoretical density of the desired titanate powder.