Murata Manufacturing Co., Ltd.

Junichi Imanari

Yukio Sakabe

Goro Nishioka

Masaru Fujino

A dielectric ceramic composition consists essentially of a main component composed of a solid solution of a three component system Pb(Mg.sub.1/3 Nb.sub.2/3)O.sub.3 -Pb(Zn.sub.1/3 Nb.sub.2/3)O.sub.3 -PbTiO.sub.3, characterized in that said main component consists essentially of 68.05 to 69.60 wt % of Pb.sub.3 O.sub.4, 2.41 to 4.00 wt % of MgO, 0.08 to 3.15 wt % of ZnO, 24.01 to 26.66 wt % of Nb.sub.2 O.sub.5, and 0.13 to 2.59 wt % of TiO.sub.2, and has a set of compositional proportions of the three components falling within an area defined by a polygon ABCD encompassed by points A, B, C, and D in FIG. 1, and that a subsidiary component consisting essentially of MgO is incorporated into said main component in an amount of not more than 1.0 part by weight (except 0 part by weight) with respect to 100 part by weight of the main component. The composition may further contain, as a part of the subsidiary component, manganese and/or a compound represented by the general formula: A(Cu.sub.1/2 W.sub.1/2)O.sub.3 (wherein A is one or more elements selected from the group consisting of Pb, Ba, Sr, and Ca).

Dielectric ceramic composition

A dielectric ceramic composition of a ternary system Pb(Ni.sub.1/3 Nb.sub.2/3)O.sub.3 --PbTiO.sub.3 --Pb(Zn.sub.1/2 W.sub.1/2)O.sub.3 comprises a solid solution having a composition represented by the general formula:

A dielectric ceramic composition of a ternary component system, Pb(Ni.sub.1/3 Nb.sub.2/3)O.sub.3 -PbTiO.sub.3 -Pb(Fe.sub.2/3 W.sub.1/3)O.sub.3. The three components, Pb(Ni.sub.1/3 Nb.sub.2/3)O.sub.3, PbTiO.sub.3 and Pb(Fe.sub.2/3 W.sub.1/3)O.sub.3 have the compositional proportion expressed by the general formula:

A dielectric ceramic composition consists essentially of Pb(Ni.sub.1/3 Nb.sub.2/3)O.sub.3, PbTiO.sub.3, Pb(Zn.sub.1/2 W.sub.1/2)O.sub.3 and Pb(Cu.sub.1/3 Nb.sub.2/3)O.sub.3, the mole percentages of said four components being as follows:

A dielectric ceramic composition consists essentially of Pb(Ni.sub.1/3 Nb.sub.2/3)O.sub.3, PbTiO.sub.3, Pb(Zn.sub.1/2 W.sub.1/2)O.sub.3 and M(Cu.sub.1/3 Nb.sub.2/3)O.sub.3 (wherein M represents at least one element selected from the group consisting of Ba, Sr and Ca), the mole percentages of said four components being as follows:

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Nagaokakyo, Japan

Junichi Imanari