Method for producing barium titanate-based powder, and multilayer ceramic capacitor
A method for producing a barium titanate-based powder that includes mixing a titanium compound and a barium compound together with water and chlorine to prepare a slurry, and temporarily firing the mixture of the titanium compound and the barium compound which is contained in the slurry to provide a barium titanate-based powder. The chlorine in the slurry is in the form of chlorine ions in a ratio of 230 to 1100 wt ppm based on the amount of the barium titanate-based powder to be synthesized.
1. A method for producing a barium titanate-based powder, the method comprising:
mixing a titanium compound and a barium compound together with water and chlorine to prepare a first slurry, the chlorine being in the form of chlorine ions in a ratio of 230 to 1100 wt ppm based on an amount of the barium titanate-based powder to be produced;
firing the mixture of the titanium compound and the barium compound contained in the first slurry to produce the barium titanate-based powder;
dispersing the produced barium titanate-based powder in a second slurry; and
removing chlorine contained in or on the barium titanate-based powder obtained after the firing of the mixture of the titanium compound and the barium compound contained in the first slurry and after dispersing the produced barium titanate-based powder in the second slurry.
2. The method for producing a barium titanate-based powder according to claim 1 , wherein the chlorine is added as ammonium chloride to form the first slurry.
3. The method for producing a barium titanate-based powder according to claim 1 , wherein the titanium compound is titanium dioxide.
4. The method for producing a barium titanate-based powder according to claim 3 , wherein the titanium dioxide comprises grains having a specific surface area of 30 to 50 m 2 /g.
5. The method for producing a barium titanate-based powder according to claim 1 , wherein the barium compound is barium carbonate.
6. The method for producing a barium titanate-based powder according to claim 5 , wherein the barium carbonate comprises grains having a specific surface area of 10 to 30 m 2 /g.
7. The method for producing a barium titanate-based powder according to claim 1 , further comprising drying the first slurry before the firing is carried out.
8. The method for producing a barium titanate-based powder according to claim 7 , wherein the drying is carried out at 100 to 200° C. for 12 to 36 hours.
9. The method for producing a barium titanate-based powder according to claim 1 , wherein the firing is carried out at 800 to 1100° C. for 1 to 5 hours.
10. The method for producing a barium titanate-based powder according to claim 1 , wherein the chlorine contained in or on the barium titanate-based powder is removed until a content of the chlorine contained in or on the barium titanate-based powder is reduced to 100 wt ppm or less.
11. The method for producing a barium titanate-based powder according to claim 1 , wherein the chlorine is removed by passing the second slurry in which the produced barium titanate-based powder is dispersed through an ion exchange resin.
12. The method for producing a barium titanate-based powder according to claim 1 , wherein the chlorine is removed with the use of an ion exchange resin.
13. A multilayer ceramic capacitor which is produced using the barium titanate-based powder obtained by the method according to claim 1 .