Claims
- 1. A semiconductor ceramic composition of a barium titanate system having a specific resistance of 400 ohm-cm or less, consisting essentially of a main component containing a small amount of one or more semiconductor- forming elements, and additives of manganese oxide and silica, said main component consisting essentially of 30 to 95 mol % of BaTiO.sub.3, 3 to 25 mol % of CaTiO.sub.3, 1 to 30 mol % of SrTiO.sub.3 and 1 to 50 mol % of PbTiO.sub.3, said semiconductor-forming elements being selected from the group consisting of rare earth elements, Nb, Bi, Sb, W and Th, and being present in an amount of 0.2 to 1.0 mol %, wherein the content of manganese oxides is 0.03 to 0.10 mol % in terms of Mn with respect to one mole of the main component, and wherein the content of silica is 0.5 to 5 mol % in terms of SiO.sub.2 with respect to one mole of the main component.
- 2. A semiconductor ceramic composition according to claim 1 wherein the main component having a composition expressed by the general formula:
- (Ba.sub.1-x-y-z Ca.sub.x Sr.sub.y Pb.sub.z).sub.m TiO.sub.3
- where x, y and z are respective mole fractions, 1-x-y-z is 0.30 to 0.95, x is 0.03 to 0.25, y is 0.01 to 0.30, z is 0.01 to 0.50 mol %, m is a mole ratio of (Ba.sub.1-x-y-z Ca.sub.x Sr.sub.y Pb.sub.z) to Ti and takes a value of 0.99 to 1.03.
- 3. A semiconductor ceramic composition according to claim 1 wherein said main component consisting essentially of 82 mol % of BaTiO.sub.3, 5 mol % of CaTiO.sub.3, 8 mol % of SrTiO.sub.3 and 5 mol % of PbTiO.sub.3.
- 4. A semiconductor ceramic composition according to claim 1 wherein said main component consisting essentially of 67 mol % of BaTiO.sub.3, 20 mol % of CaTiO.sub.3, 8 mol % of SrTiO.sub.3 and 5 mol % of PbTiO.sub.3.
- 5. A semiconductor ceramic composition according to claim 1 wherein said main component consisting essentially of 65 mol % of BaTiO.sub.3, 15 mol % of CaTiO.sub.3, 15 mol % of SrTiO.sub.3 and 5 mol % of PbTiO.sub.3.
- 6. A semiconductor ceramic composition according to claim 1 wherein said main component consisting essentially of 52 mol % of BaTiO.sub.3, 15 mol % of CaTiO.sub.3, 8 mol % of SrTiO.sub.3 and 25 mol % of PbTiO.sub.3.
- 7. A semiconductor ceramic composition according to claim 1 wherein said main component consisting essentially of 32 mol % of BaTiO.sub.3, 15 mol % of CaTiO.sub.3, 8 mol % of SrTiO.sub.3 and 45 mol % of PbTiO.sub.3.
Priority Claims (1)
Number |
Date |
Country |
Kind |
56-43727 |
Mar 1981 |
JPX |
|
Parent Case Info
This is a continuation-in-part application of Ser. No. 359,901, filed on Mar. 19, 1982, now abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
3975307 |
Metsuo et al. |
Aug 1976 |
|
4014822 |
Fujikawa |
Mar 1977 |
|
4096098 |
Umeya et al. |
Jun 1978 |
|
Foreign Referenced Citations (6)
Number |
Date |
Country |
40391 |
Nov 1981 |
EPX |
2361230 |
Jun 1975 |
DEX |
52-41896 |
Mar 1977 |
JPX |
54-125499 |
Sep 1979 |
JPX |
1527060 |
Oct 1978 |
GBX |
585139 |
Dec 1977 |
SUX |
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
359901 |
Mar 1982 |
|