Dielectric composition and multilayer ceramic capacitor containing the same

A dielectric composition comprising:

• a barium titanate-based powder particle material comprising dielectric grains having a core-shell structure including a core and a shell around the core,
• wherein the shell has a structure in which titanium is partially substituted with an element M having the same oxidation number as that of titanium and having an ionic radius different from that of titanium, and the element M is at least one of Sn and Hf, and
• a content of M in the shell is higher than a content of M in the core,
• wherein the core includes the at least one Sn and Hf, and a content ratio of the at least one Sn and Hf in the core to that in the shell is 1/5 or more.

A multilayer ceramic capacitor comprising:

• a ceramic body including dielectric layers and first and second internal electrodes disposed to face each other with respective dielectric layers interposed therebetween;
• and
• first and second external electrodes disposed on an external surface of the ceramic body,
• wherein each at least one of the dielectric layer layers contains a barium titanate-based powder particle material comprising dielectric grains having a core-shell structure including a core and a shell around the core, the shell having a structure in which titanium is partially substituted with an element having the same oxidation number as that of the titanium in the barium titanate-based powder particle material and having an ionic radius different from that of the titanium in the barium titanate-based powder particle material, and
• a number of dielectric grains of which the shell covers at least 50% 30% of the surface of the core before sintering is within in a range of 35 35% to 85% of the overall number of dielectric grains.

A multilayer ceramic capacitor comprising:

• a ceramic body including dielectric layers and first and second internal electrodes disposed to face each other with respective dielectric layers interposed therebetween;
• and
• first and second external electrodes disposed on an external surface of the ceramic body,
• wherein at least one of the dielectric layers contains a barium titanate-based material having core-shell structures, each of the core-shell structures including a core and a shell around the core, the shell having a structure in which titanium is partially substituted with an element having an ionic radius different from that of titanium in the barium titanate-based material, and
• a number of core-shell structures of which the shell covers at least 30% of the surface of the core is in a range of 35% to 85% of an overall number of core-shell structures.