Multilayer ceramic capacitor and method for producing the same
A multilayer ceramic capacitor having inner electrodes with a Ni-Metal A alloy, the Metal A being selected from Fe, V, Y, and Cu and dissolved in the Ni to form a solid solution. The percentage of the Metal A with respect to the total amount of Metal A and Ni in near-surface regions located at a depth of 2 nm from a surface of the inner electrode in contact with an adjacent ceramic dielectric layer is 1.4 or more atom %, and XA−YA≥1.0, where XA represents the atomic percentage of Metal A in the near-surface regions and YA represents the atomic percentage of Metal A in mid-thickness regions of the inner electrodes. A method for producing a multilayer ceramic capacitor includes annealing the ceramic multilayer body under specific conditions to thereby increase, in the inner electrodes, the percentage of Metal A in the near-surface regions.
1. A multilayer ceramic capacitor comprising:
a ceramic multilayer body including a stack of a plurality of ceramic dielectric layers and a plurality of inner electrodes arranged opposing each other with a respective ceramic dielectric layer of the plurality of ceramic dielectric layers interposed therebetween; and
outer electrodes disposed on an outer surface of the ceramic multilayer body, each outer electrode being in electrical connection with a respective set of inner electrode of the plurality inner electrodes,
the inner electrodes including a Ni-Metal A alloy, wherein Metal A is at least one metal selected from the group consisting of Fe, V, Y, and Cu,
a percentage of Metal A with respect to a total amount of Metal A and Ni in near-surface regions of the plurality of inner electrodes is 1.4 or more atom %, each of the near-surface regions being a region at a depth of within 2 nm from a surface in contact with an adjacent one of the respective ceramic dielectric layers, and
XA−YA≥ 1.0
where XA represents an atomic percentage of Metal A in the near-surface regions and YA represents an atomic percentage of Metal A in mid-thickness regions of the plurality of inner electrodes.
2. The multilayer ceramic capacitor according to claim 1 , wherein the plurality of inner electrodes have a thickness defined as T, and each of the mid-thickness regions is located 0.2T or more inward from each surface of the plurality of inner electrodes in a thickness direction thereof.
3. The multilayer ceramic capacitor according to claim 1 , wherein the Ni-Metal A alloy contains a solid solution of Ni and the Metal A.
4. The multilayer ceramic capacitor according to claim 1 , wherein the plurality of inner electrodes contain a co-material.
5. The multilayer ceramic capacitor according to claim 4 , wherein the co-material contains at least some constituent elements of a ceramic material of the ceramic dielectric layers.