Tdk Corporation

Shinsuke Hashimoto

Yasuhiro Ito

Tatsuya Ishii

Nobuto Morigasaki

Dan Sakurai

Takuma Ariizumi

Tomoaki Nonaka

Hiroshi Sasaki

Tomohiro Yamashita

Tsutomu Odashima

Tetsuo Takaishi

Matsumi Watanabe

Takahiro Harada

Masato Konno

Momoyo Nitta

A dielectric ceramic composition having good characteristic even under high electric field intensity, and particularly good IR characteristic and high temperature accelerated lifetime. The present invention is a dielectric ceramic composition comprising,

Dielectric ceramic composition and multilayer ceramic capacitor

A dielectric ceramic composition has good characteristics even under the high electric field intensity, and particularly good IR characteristic and the high temperature accelerated lifetime. The dielectric ceramic composition has a main component having a perovskite type compound shown by a compositional formula (BaSrCa)(TiZr)O, a first sub component having oxides of a rare earth element R, a second sub component as a sintering agent, wherein the dielectric particles has dielectric particles having high diffusion rate of the rare earth element, preferably of a complete solid solution particle, and when a concentration of Ti atom in the diffusion phase is 100 atom %, then an average concentration of the rare earth element R in the diffusion phase is 5 atom % or more, and an average concentration of Zr in the diffusion phase is 10 atom % or more.

A purpose of the present invention is to provide a dielectric ceramic composition which is available to obtain a multilayer ceramic capacitor having a high specific permittivity and a small temperature change of capacitance. A dielectric ceramic composition comprises a dielectric main component composed of 86.32 to 97.64 mol % of BaTiO, 0.01 to 10.00 mol % of YOand 0.01 to 10.00 mol % of MgO and 0.001 to 0.200 mol % of VO, 0.01 to 1.0 mol % of more than one kind of a first additive selected from a group composed of MnO, CrO, CoO, 0.5 to 10.0 mol % of a second additive which is {Ba&#x3b1;, Ca (1&#x2212;&#x3b1;)}SiO(note, 0&#x2266;&#x3b1;&#x2266;1), and Sr: 10 to 500 ppm, S: 10 to 50 ppm, Al: 10 to 50 ppm, Fe: 10 to 50 ppm, Zr: 100 to 800 ppm, Y: 10 to 100 ppm, Hf: 10 to 100 ppm to 100 parts by weight of BaTiO.

Dielectric ceramic composition

A production method of barium titanate according to the present invention comprises steps of preparing powder mixture of barium carbonate powder and titanium oxide powder and firing the powder mixture. The temperature of the powder mixture is raised to firing temperature at 100&#xb0; C./minute or more in the range of 400&#xb0; C. to 700&#xb0; C.; and maximum temperature at firing is 700&#xb0; C. or more. The present invention aims at providing a production method, wherein grain growth of barium carbonate particle can be controlled in temperature rising process when producing barium titanate by a solid phase reaction of barium carbonate and titanium oxide; and homogeneous barium titanate powder with small particle size can be produced with excellent energy efficiency.

Production method of barium titanate

A dielectric ceramic composition comprising 100 moles of barium titanate as the main component, and furthermore comprising with respect to 100 moles of the main component 0.1 to 3 moles of a first subcomponent including a magnesium oxide, 0.01 to 0.5 mole (note that 0.5 is not included) of a second subcomponent including a yttrium oxide, 0.01 to 0.2 mole of a third subcomponent including a vanadium oxide, and 0.5 to 10 moles of a glass component including a silicon oxide as the main component; wherein a manganese oxide and a chrome oxide are substantially not included, and an average particle diameter of dielectric particles is 0.35 &#x3bc;m or smaller.

Dielectric ceramic composition and electronic device

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Tokyo, Japan

Shinsuke Hashimoto