| 摘要 |
PURPOSE:To enable an increase of dielectric constant in spite of a small grain size by making barium titanate, in which a specific amount of alkali metal oxides are contained as an impurity, contain specific amount of specific compounds. CONSTITUTION:In 100 mole% of barium titanate which contains alkali metal oxides as an impurity by 0.03weight% or less, at least one kind selected of lanthanum oxide, cerium oxide, neodymium oxide praseodymium oxide, samarium oxide is made to be contained by 2.5 to 5.0mole%. Furthermore, zirconium oxide, tin oxide and titanium are made to be contained by 2.5 to 5.0mole% calculated in terms of (Zr1-a--bSnaTib)O2 (where a>,b>=0.0<a+b<=1.0). In the manufacture of dielectric porcelain, a mold body composed of this composition is baked in the atmosphere with oxygen concentration of 60% or more. |
