| 摘要 |
This invention provides a piezoelectric actuator, concerning which a substrate and a piezoelectric film layer will never erode, the area of which can be enlarged, and which has a flat top surface, and this invention provides an ink jet printing head, a printer, a method for manufacturing a piezoelectric actuator, and a method for manufacturing an ink jet printing head. <??>A piezoelectric actuator comprising a piezoelectric film held between a lower electrode and an upper electrode is characterized in that columnar crystal grains of piezoelectric ceramic which composes the piezoelectric actuator are random-oriented in a film thickness direction, and that a mean diameter of the columnar crystal grains is in the range of 100 nm to 15000 nm. <??>The step of forming precursor films (411, 412,...), which are composed of metal and oxygen, over a lower electrode (32) is followed by the step of giving hydrothermal treatment by dipping the precursor films (411, 412,...) in an alkaline solution (101), which has 2 MÄmol/lÜ or less, more preferably 0.1 MÄmol/lÜ or less, concentration of a given alkaline solute, and by promoting the crystallization under certain conditions. Since a strong alkaline solution is not used, there is no fear that a substrate or a piezoelectric film layer may erode. <IMAGE> |
