Dielectric ceramic composition.

摘要

A dielectric ceramic composition consisting essentially of a BaO-TiO2-WO3 ternary system wherein molar percentages of BaO, TiO2 and WO3 are within the range enclosed by a line joining the points of A(21.5, 78.5, 0), B(40.0, 30.0, 30.0), C(37.0, 30.0, 33.0), D(20.0, 75.0, 5.0), E(21.5, 75.0, 3.5) and A of a composition diagram shown in the attached FIGURE, the range excluding molar percentages of BaO, TiO2 and WO3 laying on a line joining said points A, E and D. In the dielectric ceramic composition, up to 10 mole % of TiO2 may be replaced by tetravalent metal oxide and, further, MnO is contained in amounts of 3 mole % or less with respect to 100 mole % of the sum of BaO, TiO2 and WO3. Since the dielectric ceramic composition has a beneficial combination of dielectric properties, particlularly a high Q, properly small dielectric constant and sufficiently small temperature coefficent of resonant frequency, tau f, and tau f, can be adjusted to a desired value in the vicinity of 0 ppm/ DEG C, it is especiallygreatly useful at the microwave range.