THIN FILM PIEZOELECTRIC ELEMENT, THIN FILM PIEZOELECTRIC ACTUATOR, THIN FILM PIEZOELECTRIC SENSOR, HARD DISK DRIVE, AND INK-JET PRINTER DEVICE

• Main Authors: MAEJIMA KAZUHIKO, SAKUMA HITOSHI
• Format: Patent
• Language: English; Japanese
• Published: 30.07.2015
• Subjects: CORRECTION OF TYPOGRAPHICAL ERRORS; ELECTRICITY; GYROSCOPIC INSTRUMENTS; i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; LINING MACHINES; MEASURING; MEASURING DISTANCES, LEVELS OR BEARINGS; MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER,MECHANICAL EFFICIENCY, OR FLUID PRESSURE; NAVIGATION; PERFORMING OPERATIONS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY; PHYSICS; PRINTING; SELECTIVE PRINTING MECHANISMS; STAMPS; SURVEYING; TESTING; TRANSPORTING; TYPEWRITERS

PROBLEM TO BE SOLVED: To provide a thin film piezoelectric element which enables the further increase in quantity of displacement by providing convexo-concave shapes in a ground plane of a piezoelectric thin film of a thin film piezoelectric element on condition that the thin film piezoelectric element remain definite in two-dimensional shape, and layer structure.SOLUTION: A thin film piezoelectric element comprises: a pair of electrode layers; and a piezoelectric thin film sandwiched between the pair of electrode layers. The surface roughness P-V at the interface of the piezoelectric thin film, and at least one of the pair of electrode layers is 220-500 nm. In addition, the surface roughness Ra of the interface is 90-220 nm. It is preferable that the surface roughness Ra be larger than the average crystal grain size of crystal grains included in the piezoelectric thin film. 【課題】薄膜圧電素子の平面形状、層構造を一定としたままで、薄膜圧電素子を構成する圧電薄膜の接地面に凹凸の形状を備え、変位量をより増大させることを目的とする。【解決手段】薄膜圧電素子は一対の電極層と前記一対の電極層に挟まれた圧電薄膜とを備え、圧電薄膜と一対の電極層の少なくとも一方との界面の表面粗さＰ−Ｖが２２０ｎｍ以上５００ｎｍ以下である。また、界面の表面粗さＲａが９０ｎｍ以上２２０ｎｍ以下であり、この表面粗さＲａは圧電薄膜を構成する結晶粒子の平均結晶粒径より大きいことが好ましい。【選択図】図１