| 摘要 |
PROBLEM TO BE SOLVED: To ensure superior dimensional stability at high temp. and high strength and to suppress deformation such as warpage by forming a perovskite type crystal structure represented by a specified formula and specifying open porosity and average pore diameter. SOLUTION: This porous ceramic sintered compact has a perovskite type crystal structure represented by the formula, La1-x Srx MnO3 (where 0.1<=x<=0.2), 20-30% open porosity and 1-3μm average pore diameter. The reason why the value (x) in lanthanum strontium manganite represented by the formula is regulated to 0.1-0.2 is that the difference in the coefft. of thermal expansion between the manganite and other electrode material is reduced in the case of 0.1<=x<=0.2. Deformation such as warpage may be caused in the case of x<0.1 or x>0.2. At the time of production, the average particle diameter of powdery starting material is preferably regulated to >=5μm in consideration of compactibility and handleability. Carbon powder used as a pore making material is preferably high purity fine powder having 1-10μm average particle diameter and 200-300m<2> /g specific surface area. Sintering temp. is regulated to 1,400-1,500 deg.C.
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