A method is provided for manufacturing a piezoelectric device including a piezoelectric element that is disposed above a diaphragm and that has a multilayer structure including a first electrode disposed above the diaphragm, a piezoelectric layer disposed on the first electrode, and a second electrode disposed on the piezoelectric layer. The method includes forming the multilayer structure including the first electrode, the piezoelectric layer, and the second electrode above the diaphragm, forming a voltage application electrode extending outwardly from an end of the second electrode to cover a region located above the piezoelectric layer in an inactive section having no second electrode, applying a voltage between the first electrode and the second electrode, and removing the voltage application electrode.

A nozzle plate includes, on a substrate: at least a base layer; an intermediate layer; and a liquid repellent layer. The base layer contains a silane coupling agent A having reactive functional groups at both terminals and including a hydrocarbon chain and a benzene ring at an intermediate part. The intermediate layer contains an inorganic oxide. The liquid repellent layer contains a fluorine (F)-containing coupling agent B.

Provided are a vibrating plate, a first electrode provided over the vibrating plate, a piezoelectric layer provided over the first electrode, and a second electrode provided over the piezoelectric layer are provided. The piezoelectric layer is interposed between the first electrode and the second electrode. The piezoelectric layer includes an active portion of which at least one end portion is defined by the first electrode, and a non-active portion provided on an outside of the end portion of the first electrode for defining the active portion. The vibrating plate includes a first vibration portion under the non-active portion and a second vibration portion on an outside of the first vibration portion. The second vibration portion includes a taper part having the thickness which is increased toward the first vibration portion.

In an embodiment, a fluid ejection device includes a thin-film layer formed over a substrate. A primer layer is formed over the thin-film layer, and a chamber layer is formed over the primer layer that defines a fluidic channel leading to a firing chamber. The fluid ejection device includes a slot that extends through the substrate and into the chamber layer through an ink feed hole in the thin-film layer. The fluid ejection device also includes a particle tolerant extension of the primer layer that protrudes into the slot. In some implementations, the particle tolerant primer layer extension extends across a full width of the slot.

An electro-mechanical transducer includes a diaphragm plate on a substrate, a first electrode on the diaphragm plate, an electro-mechanical transducer film on the first electrode, and a second electrode on the electro-mechanical transducer film. One of the first electrode and the second electrode is a common electrode. Another of the first electrode and the second electrode is an individual electrode. At least a portion of the common electrode is laminated on and in contact with the diaphragm plate. The common electrode has a plurality of holes penetrating the common electrode in a lamination direction.

A liquid discharge head includes a pressure chamber in which liquid can be stored, a diaphragm forming a bottom wall of the pressure chamber and having a nozzle opening through which liquid supplied from the pressure chamber is discharged in a first direction, and a drive element on a lower surface of the diaphragm and configured to change a volume of the pressure chamber. A protective film covers the drive element and having a first opening corresponding in position with the nozzle opening, and a liquid repellent film covers the protective film and the lower surface of the diaphragm within the first opening. The liquid repellent film has an opening aligned with the nozzle opening and has the same diameter as the nozzle opening. The liquid repellent film on the drive element is thinner than the liquid repellent film on the lower surface of the diaphragm within the first opening.

A piezoelectric body layer of a first area has (100) plane preferential orientation, and a (100) plane orientation ratio of the piezoelectric body layer of a second area is lower than a (100) plane orientation ratio of the piezoelectric body layer of the first area, when one area far from an end portion of a second electrode is the first area, and one area near the end portion of the second electrode is the second area, of two areas of the second electrode in a second direction intersecting a first direction.

A piezoelectric element includes: a first electrode formed at a vibration plate; a seed layer formed at the first electrode; a piezoelectric film containing potassium, sodium, and niobium and formed at the seed layer; and a second electrode formed at the piezoelectric film. The piezoelectric film contains lithium and one or more first transition elements. The seed layer contains bismuth. When the piezoelectric film is divided into two equal parts in a stacking direction, the second electrode side is defined as a first region, and the first electrode side is defined as a second region, a bismuth intensity obtained by SIMS measurement at a boundary between the first region and the second region is equal to or less than 1/500 of a maximum bismuth intensity obtained by the SIMS measurement of the piezoelectric film.

A droplet discharge head includes: a nozzle configured to discharge a liquid as droplets; a pressure chamber defining substrate defining a pressure chamber communicating with the nozzle; a piezoelectric element including a first electrode, a second electrode, and a piezoelectric layer containing a perovskite-type composite oxide containing potassium (K), sodium (Na), and niobium (Nb) as a main component; and a vibration plate forming a part of a wall surface of the pressure chamber and configured to vibrate by driving of the piezoelectric element. A driving frequency f [Hz] of the piezoelectric element, a piezoelectric constant d.sub.31 [m/v] of the piezoelectric element, a ratio x of a Na molar fraction to a total value of a K molar fraction and the Na molar fraction in the piezoelectric layer, and a viscosity μ [Pa.Math.s] of the liquid at 25° C. satisfy a relationship represented by a formula (1).

A liquid discharge head includes a substrate, a pressure chamber through which a first liquid and a second liquid flow while being in contact with each other, a pressure generating element configured to pressurize the first liquid, and a discharge port configured to discharge the second liquid. The substrate has a first channel and a second channel that each extend through the substrate. The first channel is used to supply the first liquid to the pressure chamber. The second channel is used to supply the second liquid to the pressure chamber. A viscosity of the second liquid is greater than a viscosity of the first liquid. An average cross-section area of the second channel is greater than an average cross-section area of the first channel.