Patent DE-102007000730-A1 (DE)
Title: Stacked piezoceramic element, useful in a fuel injection device, comprises piezoceramic layers and inner electrode layers that are alternately stacked upon the piezoceramic layers
Inventor: SUZUKI SATOSHI
IPC: H01L41/22
Filed: 2007-09-13
Abstract: Stacked piezoceramic element (Q), comprises piezoceramic layers (11) and inner electrode layers (12, 13) that are alternately stacked upon the piezoceramic layers; where: each of the inner electrode layers consists of an electrically conductive metal and a material of lead zirconate titanate (PZT) family with a B1-site substituent, in which 0.1-1 mol.% of a B1-site element of the PZT material, depicted by a basic composition (Q1) is substituted by at least a bivalent or trivalent transitional metal element M; and each of the piezoceramic layers are composed of a main component. Stacked piezoceramic element (Q), comprises piezoceramic layers (11) and inner electrode layers (12, 13) that are alternately stacked upon the piezoceramic layers; where: each of the inner electrode layers consists of an electrically conductive metal and a material of lead zirconate titanate (PZT) family with a B1-site substituent, in which 0.1-1 mol.% of a B1-site element of the PZT material, depicted by a basic composition (Q1) with a formula (AB1O 3) is substituted by at least a bivalent or trivalent transitional metal element M; and each of the piezoceramic layers are composed of a main component, which is made up of the PZT material, in which the B1-site element is not substituted. An independent claim is included for a process for obtaining (Q) comprising fabrication of the non-sintered and molded ceramic layers (green body) (15) containing a first ceramic raw material, which after a sintering step forms the material of the PZT family of piezoceramic layers; fabrication of an electrode material by mixing an electrically conductive metal powder and a second ceramic raw material, which after a sintering step forms the material of the PZT family with B-site substituent of the inner electrode layers; application of the electrode material on each of the non-sintered and molded ceramic layers; stacking of the non-sintered and molded ceramic layers that are coated with the electrode material, so as to form an intermediate stacked structure; and sintering of the intermediate stacked structure, where the step of making the electrode material uses a second ceramic raw material comprising at least one of the following alternatives: a composite material composed of an initial material mixture containing ceramic raw materials, which are blended in a mixing ratio that forms the material of the PZT family in a specified composition after a sintering step, an oxidative product of the transition metal element M, which is added to the initial material mixture in a mixing ratio of 0.1-1 mol.% of a B-site element of the material of PZT family to be substituted by the transition metal element M, a calcined composite material of a initial material powder, which is composed of a calcined initial material powder that was obtained by calcinations and powdering of the composite material, and a calcined raw material powder composite, which consists of a calcined raw material powder, by calcination of raw material mixture and powder, and an oxide product of the transition metal element M together in a mixing ratio mixed, which allows 0.1-1 mol.% of the B-site element of the material PZT family to be substituted by the transition metal element M.