There are provided a piezoelectric film-attached substrate and piezoelectric element, which include, on a substrate in the following order, a lower electrode layer, a piezoelectric film containing a perovskite-type oxide containing lead as a main component of an A site, and a buffer layer, where the buffer layer contains a metal oxide represented by M.sub.dN.sub.1-dO.sub.e. Here, M consists of one or more metal elements substitutable for the A site of the perovskite-type oxide and has an electronegativity of less than 0.95. In a case of 0<d<1 and in a case where the electronegativity is denoted by X, 1.41X−1.05≤d≤A1.Math.exp(−X/t1)+y0, where A1=1.68×10.sup.12, t1=0.0306, and y0=0.59958.

The invention provides a process for forming crack-free dielectric films on a substrate. The process comprises the application of a dielectric precursor layer of a thickness from about 0.3 μm to about 1.0 μm to a substrate. The deposition is followed by low temperature heat pretreatment, prepyrolysis, pyrolysis and crystallization step for each layer. The deposition, heat pretreatment, prepyrolysis, pyrolysis and crystallization are repeated until the dielectric film forms an overall thickness of from about 1.5 μm to about 20.0 μm and providing a final crystallization treatment to form a thick dielectric film. The process provides a thick crack-free dielectric film on a substrate, the dielectric forming a dense thick crack-free dielectric having an overall dielectric thickness of from about 1.5 μm to about 20.0 μm.

The invention provides a process for forming crack-free dielectric films on a substrate. The process comprises the application of a dielectric precursor layer of a thickness from about 0.3 μm to about 1.0 μm to a substrate. The deposition is followed by low temperature heat pretreatment, prepyrolysis, pyrolysis and crystallization step for each layer. The deposition, heat pretreatment, prepyrolysis, pyrolysis and crystallization are repeated until the dielectric film forms an overall thickness of from about 1.5 μm to about 20.0 μm and providing a final crystallization treatment to form a thick dielectric film. The process provides a thick crack-free dielectric film on a substrate, the dielectric forming a dense thick crack-free dielectric having an overall dielectric thickness of from about 1.5 μm to about 20.0 μm.

A liquid discharge head includes a nozzle plate, a substrate, a diaphragm, and a piezoelectric element. The nozzle plate includes a nozzle from which liquid is discharged. The substrate is disposed on the nozzle plate and includes a pressure chamber communicating with the nozzle. The diaphragm is disposed on a first side of the substrate opposite a second side of the substrate on which the nozzle plate is disposed, the diaphragm constituting one wall of the pressure chamber. The piezoelectric element is disposed on the diaphragm to deform the diaphragm to discharge liquid in the pressure chamber from the nozzle. The piezoelectric element includes a first electrode, a piezoelectric film, and a second electrode. The first electrode is disposed on the diaphragm. The piezoelectric film is disposed on the first electrode.

A piezoelectric ceramic has a primary phase constituted by ceramic grains of perovskite crystal structure containing Pb, Nb, Zn, Ti, and Zr, and a secondary phase constituted by ZnO grains present sporadically in the primary phase. The piezoelectric ceramic of high kr and high specific dielectric constant can be sintered at low temperature and exhibit minimal characteristics variations.

A piezoelectric ceramic has a primary phase constituted by ceramic grains of perovskite crystal structure containing Pb, Nb, Zn, Ti, and Zr, and a secondary phase constituted by ZnO grains present sporadically in the primary phase. The piezoelectric ceramic of high kr and high specific dielectric constant can be sintered at low temperature and exhibit minimal characteristics variations.

A composition for forming a PZT-based piezoelectric film formed of Mn-doped composite metal oxides is provided, the composition including: PZT-based precursors containing metal atoms configuring the composite metal oxides; a diol; and polyvinylpyrrolidone, in which when a metal atom ratio in the composition is shown as Pb:Mn:Zr:Ti, the PZT-based precursors are contained so that a metal atom ratio of Pb is satisfied to be from 1.00 to 1.20, a metal atom ratio of Mn is satisfied to be equal to or greater than 0.002 and less than 0.05, a metal atom ratio of Zr is satisfied to be from 0.40 to 0.55, a metal atom ratio of Ti is satisfied to be from 0.45 to 0.60, and the total of Zr and Ti in a metal atom ratio is 1.

A composition for forming a PZT-based piezoelectric film formed of Mn-doped composite metal oxides is provided, the composition including: PZT-based precursors containing metal atoms configuring the composite metal oxides; a diol; and polyvinylpyrrolidone, in which when a metal atom ratio in the composition is shown as Pb:Mn:Zr:Ti, the PZT-based precursors are contained so that a metal atom ratio of Pb is satisfied to be from 1.00 to 1.20, a metal atom ratio of Mn is satisfied to be equal to or greater than 0.002 and less than 0.05, a metal atom ratio of Zr is satisfied to be from 0.40 to 0.55, a metal atom ratio of Ti is satisfied to be from 0.45 to 0.60, and the total of Zr and Ti in a metal atom ratio is 1.

Provided is a piezoelectric film formed by a vapor phase growth method, the piezoelectric film containing:

a perovskite oxide in which a perovskite oxide represented by the following formula P is doped with Si in an amount of from 0.2 mol % to less than 0.5 mol %, wherein a ratio of a peak intensity of a pyrochlore phase to a sum of peak intensities in respective plane orientations of (100), (001), (110), (101) and (111) of a perovskite phase measured by an X-ray diffraction method is 0.25 or less:

A.sub.1+δ[(Zr.sub.xTi.sub.1−a).sub.1−aNb.sub.a]O.sub.y  Formula P

wherein, in formula P, A is an A-site element primarily containing Pb; Zr, Ti, and Nb are B-site elements; x is more than 0 but less than 1; a is 0.1 or more but less than 0.3.

Provided is a piezoelectric film formed by a vapor phase growth method, the piezoelectric film containing:

a perovskite oxide in which a perovskite oxide represented by the following formula P is doped with Si in an amount of from 0.2 mol % to less than 0.5 mol %, wherein a ratio of a peak intensity of a pyrochlore phase to a sum of peak intensities in respective plane orientations of (100), (001), (110), (101) and (111) of a perovskite phase measured by an X-ray diffraction method is 0.25 or less:

A.sub.1+δ[(Zr.sub.xTi.sub.1−a).sub.1−aNb.sub.a]O.sub.y  Formula P

wherein, in formula P, A is an A-site element primarily containing Pb; Zr, Ti, and Nb are B-site elements; x is more than 0 but less than 1; a is 0.1 or more but less than 0.3.