Abstract: The invention provides a method for producing barium titanate powder comprising the steps of: adding an aqueous slurry of anatase hydrous titanium oxide having a BET specific surface area in the range of 200 m2/g to 400 m2/g and a half width of diffraction peak of (101) plane in the range of 2.3° to 5.0° as measured by X-ray diffraction to an aqueous solution of barium hydroxide while maintaining the aqueous solution of barium hydroxide at a temperature in the range from 80° C. to the boiling point thereof under normal pressure to cause a reaction of the barium hydroxide with the hydrous titanium oxide to provide an aqueous slurry of barium titanate precursor; and subjecting the barium titanate precursor thus obtained to hydrothermal treatment over a period of not less than 24 hours to provide barium titanate particles.

Abstract: The invention provides a method for producing barium titanate powder comprising the steps of: adding an aqueous slurry of anatase hydrous titanium oxide having a BET specific surface area in the range of 200 to 400 m2/g and a half width of diffraction peak of (101) plane in the range of 2.3° to 5.0° as measured by X-ray diffraction to an aqueous solution of barium hydroxide while maintaining the aqueous solution of barium hydroxide at a temperature in the range from 80° C. to the boiling point thereof under normal pressure to cause a reaction of the barium hydroxide with the hydrous titanium oxide to provide an aqueous slurry of barium titanate precursor; and subjecting the barium titanate precursor thus obtained to hydrothermal treatment over a period of time shorter than 24 hours to provide barium titanate particles.

Abstract: The invention provides a method for producing barium titanate powder comprising the steps of: adding an aqueous slurry of anatase hydrous titanium oxide having a BET specific surface area in the range of 200 m2/g to 400 m2/g and a half width of diffraction peak of (101) plane in the range of 2.3° to 5.0° as measured by X-ray diffraction to an aqueous solution of barium hydroxide while maintaining the aqueous solution of barium hydroxide at a temperature in the range from 80° C. to the boiling point thereof under normal pressure to cause a reaction of the barium hydroxide with the hydrous titanium oxide to provide an aqueous slurry of barium titanate precursor; and subjecting the barium titanate precursor thus obtained to hydrothermal treatment over a period of not less than 24 hours to provide barium titanate particles.

Abstract: The invention provides a method for producing barium titanate powder comprising the steps of: adding an aqueous slurry of anatase hydrous titanium oxide having a BET specific surface area in the range of 200 to 400 m2/g and a half width of diffraction peak of (101) plane in the range of 2.3° to 5.0° as measured by X-ray diffraction to an aqueous solution of barium hydroxide while maintaining the aqueous solution of barium hydroxide at a temperature in the range from 80° C. to the boiling point thereof under normal pressure to cause a reaction of the barium hydroxide with the hydrous titanium oxide to provide an aqueous slurry of barium titanate precursor; and subjecting the barium titanate precursor thus obtained to hydrothermal treatment over a period of time shorter than 24 hours to provide barium titanate particles.

Abstract: The invention provides a process for production of powder of perovskite compound which comprises: the first step for obtaining an aggregate of perovskite compound which comprises at least one A group element selected from the group consisting of Mg, Ca, Sr, Ba and Pb and at least one B group element selected from the group consisting of Ti, Zr, Hf and Sn, and which is represented by the general formula ABO3 wherein A is at least one A group element and B is at least one B group element; and the second step for heating the aggregate of perovskite compound obtained in the first step in a solvent at a temperature in a range from 30° C. to 500° C. whereby disintegrating the aggregate.

Abstract: The invention provides a process for production of a composition comprising a perovskite structure compound, the process comprising: a first process to heat a hydrous oxide of at least one B group element selected from the group consisting of Ti, Zr, Hf, and Sn at a temperature within a range of 80 to 300° C. in the presence of an aqueous medium so as to dehydrate the hydrous oxide; and a second process to heat a reaction product obtained in the first process and a hydroxide of at least one A group element selected from the group consisting of Ba, Sr, Ca, Mg and Pb at a temperature within a range of 100 to 300° C. in the presence of an aqueous medium. The process provides a composition comprising an ABO3 compound in the form of uniform and fine spherical particles which have an average particle diameter of 1 ?m or less, preferably within a range of 0.01 to 0.5 ?m, high crystallinity, and a controlled A/B ratio as desired, as well as few internal pores in the crystalline particles.

Abstract: The invention provides a process for production of a composition comprising a perovskite structure compound, the process comprising: a first process to heat a hydrous oxide of at least one B group element selected from the group consisting of Ti, Zr, Hf, and Sn at a temperature within a range of 80 to 300° C. in the presence of an aqueous medium so as to dehydrate the hydrous oxide; and a second process to heat a reaction product obtained in the first process and a hydroxide of at least one A group element selected from the group consisting of Ba, Sr, Ca, Mg and Pb at a temperature within a range of 100 to 300° C. in the presence of an aqueous medium. The process provides a composition comprising an ABO3 compound in the form of uniform and fine spherical particles which have an average particle diameter of 1 ?m or less, preferably within a range of 0.01 to 0.5 ?m, high crystallinity, and a controlled A/B ratio as desired, as well as few internal pores in the crystalline particles.

Abstract: The invention provides a process for production of powder of perovskite compound which comprises: the first step for obtaining an aggregate of perovskite compound which comprises at least one A group element selected from the group consisting of Mg, Ca, Sr, Ba and Pb and at least one B group element selected from the group consisting of Ti, Zr, Hf and Sn, and which is represented by the general formula ABO3 wherein A is at least one A group element and B is at least one B group element; and the second step for heating the aggregate of perovskite compound obtained in the first step in a solvent at a temperature in a range from 30° C. to 500° C. whereby disintegrating the aggregate.