A piezoelectric ceramic, which does not contain lead as a constituent element, is characterized in that: its primary component is a perovskite compound expressed by the composition formula (Bi.sub.0.5−x/2Na.sub.0.5−x/2Ba.sub.x)(Ti.sub.1−yMn.sub.y)O.sub.3 (where 0.01≤x≤0.25, 0.001≤y≤0.020); and the coefficient of variation (CV) in grain size among the grains contained therein is 35 percent or lower. The piezoelectric ceramic presents an improved dielectric loss tangent tan δ.

An electronic device may include a first electrode, a first magnetostrictive layer coupled to the first electrode, a plurality of alternating ferromagnetic and insulating layers stacked above the first magnetostrictive layer, a second electrode electrically coupled to an intermediate ferromagnetic layer in the stack of ferromagnetic and insulating layers, a second magnetostrictive layer above the stack of ferromagnetic and insulating layers, and a third electrode electrically coupled to the second magnetostrictive layer. At least one ferromagnetic layer below the intermediate ferromagnetic layer may be switchable between different polarization states responsive to a first voltage applied across the first and second electrodes, and at least one ferromagnetic layer above the intermediate ferromagnetic layer may be switchable between different polarization states responsive to a second voltage applied across the second and third electrodes.

A semiconductor substrate with oxide single crystal heterostructures, to which a sacrificial layer, an epitaxy functional oxide thin film having a perovskite structure and a metal layer are grown on an oxide single crystal substrate, prepared another metal layer on a semiconductor substrate, and bonded the metal layer of the oxide single crystal substrate to the metal layer of the semiconductor substrate to be face each other, and separated the oxide single crystal substrate by selectively etching and removing only the sacrificial layer after the bonding.

A piezoelectric composition comprises an oxide having a perovskite structure, wherein the oxide contains bismuth, barium, iron and titanium; the X-ray diffraction pattern of the piezoelectric composition after a polarization treatment has a first peak and a second peak in the range of the diffraction angle 2θ of 38.6° or more and 39.6° or less; the diffraction angle 2θ of the first peak is smaller than the diffraction angle 2θ of the second peak; an intensity of the first peak is represented as I.sub.L; an intensity of the second peak is represented as I.sub.H; and I.sub.H/I.sub.L is 0.00 or more and 2.00 or less.

A piezoelectric thin film 3 contains a metal oxide, the metal oxide contains bismuth, potassium, titanium, iron and element M, the element M is at least one of magnesium and nickel, at least a part of the metal oxide is a crystal having a perovskite structure, and a (001) plane, a (110) plane or a (111) plane of the crystal is oriented in a normal direction dn of the surface of the piezoelectric thin film 3.

An optical element includes a primary electrode, a secondary electrode overlapping at least a portion of the primary electrode, and an electrostrictive ceramic layer disposed between and abutting the primary electrode and the secondary electrode, where the electrostrictive ceramic may be characterized by a relative density of at least approximately 99%, an average grain size of at least approximately 300 nm, a transmissivity within the visible spectrum of at least approximately 70%, and bulk haze of less than approximately 10%. Optical properties of the electrostrictive ceramic may be substantially unchanged during the application of a voltage to the electrostrictive ceramic layer and the attendant actuation of the optical element.

A piezoelectric thin film contains a lower layer and a first piezoelectric layer stacked on the lower layer. The first piezoelectric layer contains a tetragonal crystal 1 of a perovskite-type oxide. A (001) plane of the tetragonal crystal 1 is oriented in a normal direction dn of a surface of the first piezoelectric layer. A spacing of (100) planes of the tetragonal crystal 1 is a1. A spacing of (100) planes of a crystal contained in the lower layer is aL. A lattice mismatch rate between the first piezoelectric layer and the lower layer is 100×(aL−a1)/a1. The lattice mismatch rate is 3.0 to 12.1%. A rocking curve of diffracted X-rays of the (001) plane of the tetragonal crystal 1 is measured in an out-of-plane direction of the surface of the first piezoelectric layer. A FWHM of the rocking curve is 1.9 to 5.5°.

A piezoelectric thin film includes a first piezoelectric layer and a second piezoelectric layer directly stacked on the first piezoelectric layer. The first piezoelectric layer contains a tetragonal crystal 1 of a perovskite-type oxide. The second piezoelectric layer contains a tetragonal crystal 2 of a perovskite-type oxide. A (001) plane of the tetragonal crystal 1 is oriented in a normal direction do of a surface of the piezoelectric thin film. A (001) plane of the tetragonal crystal 2 is oriented in the normal direction dn of the surface of the piezoelectric thin film. An interval of the (001) plane of the tetragonal crystal 1 is c1, an interval of a (100) plane of the tetragonal crystal 1 is a1, an interval of the (001) plane of the tetragonal crystal 2 is c2, an interval of a (100) plane of the tetragonal crystal 2 is a2, c2/a2 is more than c1/a1 and c1/a1 is from 1.015 to 1.050.

Provided is an electric field-vibration generating transducer having a piezoelectric material of a high degree of displacement, and a manufacturing method thereof. The electric field-vibration generating transducer lowers the cost of production through miniaturization simultaneously with realizing excellent generating characteristics of the electric field-vibration generating transducer based on high efficiency and low voltage driving because the piezoelectric material of the high degree of displacement (high strain piezoelectrics) having a high piezoelectric constant (d.sub.33=1,000 to 6,000 pC/N), a high dielectric constant (K.sub.3.sup.T=6,000 to 15,000) as well as a low dielectric loss (tan δ<2%) is applied thereto, so the electric field-vibration generating transducer may accelerate the movement of a material, a chemical action, and a biological reaction, and may be applied to a medical device for the purpose of treatment for tumors aimed at human bodies and animals.

A piezoelectric body contains potassium, sodium, and niobium, and has a perovskite structure. A Raman shift of peaks assigned to A.sub.1g obtained by performing Raman spectroscopic analysis on a plurality of measurement regions is 400 cm.sup.−1 or more and 700 cm.sup.−1 or less. A difference between a maximum value and a minimum value of the Raman shift among the peaks in the plurality of measurement regions is 11.0 cm.sup.−1 or less.