Abstract: A piezoelectric element has a first electrode layer, a piezoelectric layer on the first electrode layer, a second electrode layer on the piezoelectric layer, a third electrode layer on part of the second electrode layer and including third metal, and an insulating layer covering at least a part of the piezoelectric layer not provided with the second electrode layer and having an aperture exposing a part of the second electrode layer. The second electrode layer has a first layer including first metal and a second layer including second metal on the first layer. The second layer is exposed in the aperture. A difference in standard redox potential between the second metal and the third metal is smaller than a difference in standard redox potential between the first metal and the third metal.

Abstract: A piezoelectric element has a first electrode layer, a piezoelectric layer on the first electrode layer, a second electrode layer on the piezoelectric layer, a third electrode layer on part of the second electrode layer and including third metal, and an insulating layer covering at least a part of the piezoelectric layer not provided with the second electrode layer and having an aperture exposing a part of the second electrode layer. The second electrode layer has a first layer including first metal and a second layer including second metal on the first layer. The second layer is exposed in the aperture. A difference in standard redox potential between the second metal and the third metal is smaller than a difference in standard redox potential between the first metal and the third metal.

Abstract: A method for manufacturing a liquid ejecting head which includes forming a first electrode on a vibration plate, forming a piezoelectric body on the first electrode, and forming a first layer having a greater thermal expansion rate than the piezoelectric body and the same conductivity as the second electrode, on the piezoelectric body. The method also includes forming a sacrifice layer on the first layer, heating the vibration plate, the first electrode, the piezoelectric body, the first layer, and the sacrifice layer to oxidize the sacrifice layer, and then cooling the vibration plate, the first electrode, the piezoelectric body, the first layer, and the sacrifice layer after the heating. Lastly, a second layer having the same conductivity as the second electrode is formed on the first layer and the sacrifice layer, after the cooling.

Abstract: The heating and the cooling are conducted. In the heating, atoms of the first layer are rearranged, distortion is removed, and the stress is alleviated. In the cooling, since the first layer has a greater thermal expansion rate than the piezoelectric body, the shrinkage of the first layer caused by the cooling is greater than that of the piezoelectric body, and the thermal stress caused by the difference in thermal expansion is applied to the piezoelectric body. The thermal stress applied to the piezoelectric body serves as a force compressing the piezoelectric body. Therefore, a compressing force is applied to the interface contacting between the first layer and the piezoelectric body to suppress creation of cracks from the interface, and, even though the deformation amount of the piezoelectric body increases, a method for manufacturing an ink jet type recording head with excellent crack resistance may be obtained.

Abstract: After the piezoelectric element forming process, in the etching process, etching is performed on a portion of at least the vibrating plate between the lead-out electrodes formed afterwards in the lead-out electrode forming process in a condition where the upper electrode film etching residual is removed and the vibrating plate is not removed. In the piezoelectric element forming process, even if the upper electrode film etching residual is generated between the lead-out electrodes, the upper electrode film etching residual is divided up due to the etching and it is possible to maintain insulation between the lead-out electrodes formed in the upper electrode film etching residual. Accordingly, it is possible to obtain the manufacturing method of the piezoelectric actuator which reduces driving defects in the piezoelectric actuator generated by short circuiting between the lead-out electrodes.

Abstract: A slit coating type application apparatus includes a holding table 20 which holds a substrate 1 on a vertically lower surface, a first liquid tank 30 which is disposed so as to face the surface of the substrate 1 held on the holding table 20 and stores a predetermined coating liquid 2, a coating head 40 which is held so as to be vertically moved in the first liquid tank 30 and has a slit-shaped nozzle 41 for flowing the coating liquid stored in the first liquid tank 30 toward the surface of the substrate 1, a second liquid tank 50 which is supported so as to be vertically moved, communicates with the first liquid tank 30 through a communicating pipe 60, and stores the coating liquid 2, and a height control unit which controls the height of the second liquid tank 50 according to the movement of the coating head 40 when the coating liquid 2 is coated on the substrate 1.