Ceramic material and capacitor comprised thereof
The invention relates to a ceramic material for capacitors. In order to achieve reduced self-heating on assembly of the material into multilayer capacitors with antiferroelectric properties and a high dielectric constant, a ceramic material of formula ┌Pb (1-r) (Ba x Sr y Ca z ) r ┘ (1-1.5a-1.5b-0.5c) (X a Y b )A c (Zr 1-d Ti d )O 3 is proposed, where X and Y both represent a rare metal earth selected from the group consisting of La, Nd, Y, Eu, Gd, Tb, Dy, Ho, Er and/or Yb; where A represents a monovalent ion; x+y+z=1; x and/or y and/or z>0; 0<r<0.3; 0<d<1; 0<a<0.2; 0<b<0.2; 0<c<0.2.
1. An antiferroelectric ceramic material with the formula
[Pb (1-r) (Ba x Sr y Ca z ) r ] (1-1.5a-1.5b-0.5c) (X a Y b )A c (Zr 1-d Ti d )O 3
wherein
X and Y are respectively a rare earth metal comprising at least one of La, Nd, Y, Eu, Gd, Tb, Dy, Ho, Er or Yb;
A represents a monovalent ion comprising Na, K, or Li;
x+y+z=1;
x and/or y and/or z>0;
0<r≦0.3;
0≦d≦1;
0≦a≦0.2;
0≦b≦0.2;
0<c≦0.2.
2. The ceramic material according to claim 1 , wherein 0.01≦r≦0.2.
3. The ceramic material according to claim 1 , wherein
0.01≦x<1;
0≦y≦0.99;
0≦z≦0.2.
4. The ceramic material according to claim 3 , wherein
y and z=0;
0.01≦r≦0.2.
5. The ceramic material according to claim 1 , wherein
0.01≦d≦0.70.
6. The ceramic material according to claim 1 , wherein X represents La and Y represents Nd.
7. A capacitor comprising a ceramic material according to claim 1 .
8. A multilayer capacitor comprising at least one layer of a material according to claim 1 .
9. The multilayer capacitor according to claim 8 , wherein inner electrodes are formed from copper.
10. An inverter for a motor drive comprising a multilayer capacitor according to claim 8 .
11. The ceramic material according to claim 1 , wherein 0.03≦d≦0.52.
12. A method for manufacturing a capacitor comprising positioning a ceramic material according to claim 1 between electrodes to reduce self-warming.
13. A method for manufacturing a multilayer capacitor comprising positioning at least one layer of a material according to claim 1 between electrodes or between multiple semiconductor diodes to reduce self-warming.