Tdk Corporation

Taku Murakami

Nobuto Morigasaki

Takuma Ariizumi

Toshihiko Kaneko

Yasuhiro Ito

Yoshitaka Nagashima

Masato Kimura

Dan Sakurai

Tsubasa Aoki

A multilayer electronic device includes an element body and a pair of external electrodes. The element body includes an interior region in which inner dielectric layers and internal electrode layers are alternately laminated and an exterior region located outside the interior region in its lamination direction. The pair of external electrodes exists on surfaces of the element body. Main-phase particles in the inner dielectric layers and outer dielectric layers of the exterior region include a main component having a perovskite crystal structure represented by a general formula of ABO. r1<r2<r1×4.0 is satisfied, in which r1 is an average particle size of the main-phase particles constituting the inner dielectric layers, and r2 is an average particle size of the main-phase particles constituting the outer dielectric layers.

Multilayer electronic device

A multilayer electronic device includes an element body including an interior region and an exterior region and a pair of external electrodes. The interior region includes inner dielectric layers and internal electrode layers laminated alternately. The exterior region is disposed outwards from the interior region in a lamination direction. The pair of external electrodes is disposed on a surface of the element body and connected to the internal electrode layers. D<D<Dand D>D>Dare satisfied, where 'RA' includes an element having a highest mole ratio among “RE” in the inner dielectric layers of a third region at a center of the interior region in the lamination direction, “RB” includes an element having a highest mole ratio among “RE” in a first region at a center of the exterior region in the lamination direction, and “RA” and “RB” are different from each other.

A dielectric ceramic composition includes a barium titanate, an oxide of an R element, an oxide of an M element, and an oxide containing Si. The R element is one or more elements selected from Eu, Gd, Tb, Dy, Y, Ho, and Yb. The M element is one or more elements selected from Mg, Ca, Mn, V, and Cr. A ratio of an amount of the oxide of the R element in terms of ROto an amount of the oxide containing Si in terms of SiOis 0.8:1 to 2.2:1. A ratio of an amount of the oxide of the M element in terms of MO to the amount of the oxide containing Si in terms of SiOis 0.2:1 to 1.8:1.50% or more of the number of dielectric particles constituting the dielectric ceramic composition is core-shell dielectric particles having a core-shell structure.

Dielectric ceramic composition and electronic device

A dielectric composition includes main-phase particles each including a main component having a perovskite crystal structure represented by a general formula of ABO. At least a part of the main-phase particles has a core-shell structure. The dielectric composition includes RA, RB, M, and Si. Each of A, B, RA, RB, and M is one or more elements selected from a specific element group. S/S>C/Cis satisfied, where Cis an RA content (mol %) to the main component in terms of RAO, and Cis an RB content (mol %) to the main component in terms of RBO, in the dielectric composition, and Sis an average RA content (mol %), and Sis an average RB content (mol %), in a shell part of the core-shell structure.

Dielectric composition, electronic device, and multilayer electronic device

A dielectric composition includes a main phase and segregation phases each including RE (at least one rare earth element). The main phase includes a main component having a perovskite crystal structure of ABO(A is one or more selected from Ba, Sr, and Ca, and B is one or more selected from Ti, Zr, and Hf). The segregation phases are classified into first segregation phases whose atomic ratio of Si to RE is 0 or more and 0.20 or less and second segregation phases whose atomic ratio of Si to the RE is more than 0.20. 0&#x2264;S1/S2&#x2264;0.10 is satisfied on a cross section of the dielectric composition, where S1 is an area ratio of the first segregation phases, and S2 is an area ratio of the second segregation phases. An atomic ratio of Si to RE in the second segregation phases is 0.80 or less on average.

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Taku Murakami