Dielectric ceramic composition and dielectric device

Patent metadata

Field	Value
Publication number	US-9530562-B2
Application number	US-201414759539-A
Country	US
Kind code	B2
Filing date	Feb 4, 2014
Priority date	Mar 27, 2013
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

To provide a dielectric ceramic composition having a high dielectric constant, i.e., 3,000 or more, at elevated temperatures at or above 150° C. and having a practically sufficient relative dielectric constant at an applied DC electric field of 2 V/μm, and to provide a dielectric device including such a dielectric ceramic composition, a dielectric ceramic composition is a composite oxide represented by formula (1):

{[(Bi s Na t ) a (Bi u K v ) b Ba c ] 1-d Na d } x Ti 1-d Nb d O 3   (1)

where a, b, c, d, s, t, u, v, and x are numbers satisfying the following conditions:
0.20≦a<0.95 0.00<b≦0.50 if 0.20<a<0.70, b<(1.20−a)/2 0.05≦c<0.60 if 0.20<a<0.70, c>(0.80−a)/2 a+b+c=1 0.02≦d<0.10 0.90≦s+u≦1.00 0.45≦t≦0.50 0.45≦v≦0.50 0.95≦x≦1.05.

First claim

The invention claimed is:

1. A dielectric ceramic composition having a composition of general formula (1):
{[(Bi s Na t ) a (Bi u K v ) b Ba c ] 1-d Na d } x Ti 1-d Nb d O 3   (1)

wherein A is at least one element selected from lithium, sodium, and potassium; and a, b, c, d, s, t, u, v, and x are numbers satisfying the following conditions:
0.20≦a<0.95
0.00<b≦0.50
if 0.20<a<0.70, b<(1.20−a)/2
0.05≦c<0.60
if 0.20<a<0.70, c>(0.80−a)/2
a+b+c=1
0.02≦d<0.10
0.90≦s+u≦1.00
0.45≦t≦0.50
0.45≦v≦0.50
0.95≦x≦1.05.

2. A dielectric device comprising the dielectric ceramic composition according to claim 1 .

Assignees

• Tdk Corp

Inventors

• Tauchi Goushi
• Imura Tomoya
• Furukawa Masahito

Classifications

• C04B2235/3298

  Bismuth oxides, bismuthates or oxide forming salts thereof, e.g. zinc bismuthate · CPC title

• G06F17/10

  Complex mathematical operations {(function generation by table look-up G06F1/03; evaluation of elementary functions by calculation G06F7/544)} · CPC title

• C04B2235/3201

  Alkali metal oxides or oxide-forming salts thereof · CPC title

• H01G4/30

  Stacked capacitors (H01G4/33 takes precedence) · CPC title

• C04B35/4682

  based on BaTiO3 perovskite phase · CPC title