Dielectric composition for a multilayer ceramic capacitor

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A multilayer ceramic capacitor of the present invention includes dielectric layers and each of the dielectric layers has a main component containing barium titanate, a first auxiliary component composed of at least one kind selected from the group consisting of MgO, CaO, BaO, and SrO, a second auxiliary component containing a silicon oxide as a main component, a third auxiliary component composed of at least one kind selected from the group consisting of V 2 O 5 , MoO 3 , and WO 3 , a fourth auxiliary component composed of an oxide of at least one kind of first rare-earth element (R1) selected from the group consisting of Sc, Er, Tm, Yb, and Lu, and a fifth auxiliary component composed of CaZrO 3 or a mixture (CaO + ZrO 2 ) of CaO and ZrO 2 . Zr diffuses in crystal grains forming the dielectric layers and, in the crystal grains each having an average grain diameter, the depth of a diffusion layer of Zr is 10 to 35% relative to the diameter of the crystal grain. Therefore, the multilayer ceramic capacitor is excellent in reliability wherein the capacitance-temperature characteristic, i.e. a time-dependent change in capacitance, satisfies the EIA standard X8R characteristic (”C/C = ±15% at -55 to +150°C) and the resistance change ratio in an acceleration test is small (average life is long).