Patent ID: 8208240
Filing Date: 2012-06-26
Classification: H01G

Abstract:
1. A multilayer ceramic capacitor comprising dielectric layers and internal electrode layers disposed alternately, the dielectric layers including a dielectric ceramic containing barium titanate as a main component, calcium, magnesium, vanadium, manganese, a first rare-earth element of yttrium or holmium and a second rare-earth element of terbium or dysprosium, wherein crystals constituting the dielectric ceramic include a first crystal group constituted by crystal grains containing the barium titanate as a main component and containing the calcium in a concentration of 0.2 atomic % or less and a second crystal group constituted by crystal grains containing the barium titanate as a main component and containing the calcium in a concentration of 0.4 atomic % or more; each crystal grains of the first crystal group and the second crystal group comprising magnesium, vanadium, manganese, the first rare-earth element and the second rare-earth element; ratios (C2/C1) of concentrations (C2) of the magnesium and the first rare-earth element contained in center portions of the crystal grains constituting the first crystal group to concentrations (C1) of the magnesium and the first rare-earth element contained in surface layers of the crystal grains constituting the first crystal group are respectively larger than ratios (C4/C3) of concentrations (C4) of the magnesium and the first rare-earth element contained in center portions of the crystal grains constituting the second crystal group to concentrations (C3) of the magnesium and the first rare-earth element contained in surface layers of the crystal grains constituting the second crystal group; and b/(a+b) is 0.5 to 0.8 where, in a polished surface obtained by polishing a surface of the dielectric ceramic, a represents an area of the crystal grains constituting the first crystal group and b represents an area of the crystal grains constituting the second crystal group.