There are provided a lead- and potassium-free piezoelectric material that has a high Curie temperature and a high mechanical quality factor and is stable in long-term driving and a piezoelectric element including the lead- and potassium-free piezoelectric material. A piezoelectric material containing a perovskite-type metal oxide having the general formula (1): Na.sub.xBa.sub.1-yNb.sub.yZr.sub.1-yO.sub.3 wherein x satisfies 0.85x0.96 and y satisfies 0.90y0.96 and a piezoelectric element including the piezoelectric material. The piezoelectric material may include the perovskite-type metal oxide and Cu, and the Cu content corresponds to 2.00 mol % or less of the amount of the perovskite-type metal oxide.

A piezoelectric ceramic plate which is slightly deformed by firing, includes a plate-shaped substrate, and an electronic component. The piezoelectric ceramic plate has a pair of main surfaces, a pair of opposing first side surfaces, and a pair of opposing second side surfaces. The pair of first side surfaces are baked surfaces, and the distance between the pair of first side surfaces measured at the center in the longitudinal direction is denoted by Lc and the distance between the pair of first side surfaces measured at ends in the longitudinal direction is denoted by Le. The ratio of the difference L between Le and Lc to Lc (L/Lc) is 1.0% or less. The piezoelectric ceramic plate is suitably used as a piezoelectric ceramic plate having an area of each of the main surfaces of 360 mm.sup.2 or more and a thickness of 150 m or less.

A barium titanate piezoelectric ceramic having good piezoelectric properties and mechanical strength and a piezoelectric element that includes the ceramic are provided. A method for making a piezoelectric ceramic includes forming a compact composed of an oxide powder containing barium titanate particles, sintering the compact, and decreasing the temperature of the compact after the sintering. The sintering includes (A) increasing the temperature of the compact to a first temperature within a temperature range of a shrinking process of the compact; (B) increasing the temperature of the compact to a second temperature within a temperature range of a liquid phase sintering process of the compact after (A); (C) decreasing the temperature of the compact to a third temperature within the temperature range of the shrinking process of the compact after (B); and (D) retaining the third temperature after (C).

Textured PMN-PZT fabricated by templated grain growth (TGG) method has a piezoelectric coefficient (d) of 3 to 5 times that of its random counterpart. By combining this TGG method with low-temperature co-firing ceramics (LTCC) techniques, co-fired multilayer textured piezoelectric ceramic materials with inner electrodes were produced at a temperature as low as 925 C., which silver could be used. Trilayer PMN-PZT ceramics prepared by this method show a strain increase of 2.5 times, a driving voltage decrease of 3 times, and an equivalent piezoelectric coefficient (d*) improvement of 10 to 15 times that of conventional random ceramic counterparts. Further, a co-fired magnetostrictive/piezoelectric/magnetostrictive laminate structure with silver inner electrode was also synthesized. The integration of textured piezoelectric microstructure with the cost-effective low-temperature co-fired layered structure achieves strong magnetoelectric coupling. These new materials have promising applications including as actuators, ultrasonic transducers, and use in energy harvesters.

An electromechanical transducer includes an electromechanical transducer film of laminated layers including a perovskite-type complex oxide represented by a general formula of ABO.sub.3; and a pair of electrodes opposed to each other with the electromechanical transducer film interposed between the pair of electrodes. In the general formula of ABO.sub.3, A includes Pb and B includes Zr and Ti. A variable ratio ?Pb of Pb, determined by Pb(max)?Pb(min), is 6% or less and a variable ratio ?Zr of Zr, determined by Zr(max)?Zr(min), is 9% or less, where an atomic weight ratio of Pb in the electromechanical transducer film is denoted by Pb/B, an atomic weight ratio of Zr in the electromechanical transducer film is denoted by Zr/B, a maximum value and a minimum value of the atomic weight ratio of Pb in a film thickness direction of the electromechanical transducer film are denoted by Pb(max) and Pb(min), respectively, and a maximum value and a minimum value of the atomic weight ratio of Zr in the film thickness direction of the electromechanical transducer film are denoted by Zr(max) and Zr(min), respectively.

A manufacturing method for an ultrasonic fingerprint sensor is provided. The method may include: preparing a sintered ceramic element under incomplete sintering conditions; forming a processed ceramic element by cutting a first surface of the sintered ceramic element along a first direction in pre-designated intervals up to such a depth that leaves a remainder region at a second surface and cutting the second surface of the sintered ceramic element along a second direction perpendicular to the first direction in pre-designated intervals up to such a depth that leaves a remainder region at the first surface; sintering the processed ceramic element under complete sintering conditions; filling an insulation material into troughs formed in the processed ceramic element by the cutting processes; and polishing the first surface and second surface to remove the remainder regions such that piezoelectric rods are exposed while arranged in an array form.

There is provided a method for manufacturing a ferroelectric thin film device including: a lower electrode film formation step of forming a lower electrode film on a substrate; a ferroelectric thin film formation step of forming a ferroelectric thin film made of a potassium sodium niobate on the lower electrode film; a ferroelectric thin film etching step of shaping the ferroelectric thin film into a desired micro-pattern by etching; and a thin film laminated substrate cleaning step of cleaning the substrate provided the ferroelectric thin film having a desired micro-pattern as a whole with a predetermined cleaning solution after the ferroelectric thin film etching step. The predetermined cleaning solution is a solution mixture containing hydrofluoric acid and ammonium fluoride, the hydrofluoric acid in the solution mixture having a molarity of 0.5 M or more and less than 5 M.

A piezoelectric/electrostrictive material is composed of Mn and a compound of Pb(Zn, Nb)O.sub.3Pb(Ni, Nb)O.sub.3Pb(Zr, Ti)O.sub.3. A ratio of a molar amount of Mn relative to a sum of respective molar amounts of Ni, Zn, Ti, Zr, Nb and Mn is at least 0.001 to no more than 0.015. A ratio of a molar amount of Nb relative to a sum of respective molar amounts of Ni and Zn is at least 2.007 to no more than 2.125.

A piezoelectric ceramic may be slightly deformed by firing, and a manufacturing method therefor, and an electronic component are disclosed. There is provided a piezoelectric ceramic including a plurality of crystal grains including a lead zirconate titanate-type crystal containing Zn, and Bi, and crystal grain boundaries existing between a plurality of the crystal grains, wherein a plurality of the crystal grains include first crystal grains, and wherein the first crystal grains have a content of at least one element of Zn and Bi present in the inside of the first crystal grains that is smaller than the content of the at least one element present in an area including the crystal grain boundaries that are in contact with the crystal grains. The piezoelectric ceramic is slightly deformed by firing and is capable of forming an electronic component which has little warp or deformation even if it is thin.

The invention relates to a method for producing ceramics having piezoelectric properties in predominantly aqueous suspending agents.