A piezoelectric device has a piezoelectric ceramic layer obtained by sintering a piezoelectric ceramic composition that contains an alkali-containing niobate type perovskite composition which is represented by (Li.sub.lNa.sub.mK.sub.1-l-m).sub.n(Nb.sub.1-oTa.sub.o)O.sub.3 (wherein 0.04l0.1, 0m1, 0.95n1.05, 0o1) and Ag component, as well as a conductor layer sandwiching the piezoelectric ceramic layer. The piezoelectric ceramic layer has Ag segregated in voids present in a sintered compact of the perovskite composition in terms of oxides relative to the perovskite composition.

A piezoelectric device has a piezoelectric ceramic layer obtained by sintering a piezoelectric ceramic composition that contains an alkali-containing niobate type perovskite composition which is represented by (Li.sub.lNa.sub.mK.sub.1-l-m).sub.n(Nb.sub.1-oTa.sub.o)O.sub.3 (wherein 0.04l0.1, 0m1, 0.95n1.05, 0o1) and Ag component, as well as a conductor layer sandwiching the piezoelectric ceramic layer. The piezoelectric ceramic layer has Ag segregated in voids present in a sintered compact of the perovskite composition in terms of oxides relative to the perovskite composition.

A nano-composite structure comprises of an amorphous matrix with embedded nano-crystallites. The nano-crystallites are precipitated from the amorphous matrix via heat treatment of a solution mixture of metal salts or metalorganic compounds to an appropriate temperature range and with a suitable duration, or heating of a mixture of non-crystalline compounds. The nano-crystallites are self-assembled in the amorphous matrix without forming agglomerates or distinguished grain boundaries. The nano-composite structure can be used for transparent display, transparent optical ceramics, protection armor, nuclear protection, pulsed power, high voltage electronics, high energy storage system and high power microwave systems.

A lithium-lanthanum-titanium oxide sintered material has a lithium ion conductivity 3.010.sup.4 Scm.sup.1 or more at a measuring temperature of 27 C., the material is described by one of general formulas (1-a)La.sub.xLi.sub.2-3xTiO.sub.3-aSrTiO.sub.3, (1-a)La.sub.xLi.sub.2-3xTiO.sub.3-aLa.sub.0.5K.sub.0.5TiO.sub.3, La.sub.xLi.sub.2-3xTi.sub.1-aM.sub.aO.sub.3-a, and Sr.sub.x-1.5aLa.sub.aLi.sub.1.5-2xTi.sub.0.5Ta.sub.0.5O.sub.3 (0.55x0.59, 0a0.2, M=at least one of Al, Fe and Ga), and concentration of S is 1500 ppm or less. The material is obtained by sintering raw material powder mixture having S content amount of 2000 ppm or less in the entirety of raw material powders for mixture, that is, titanium raw material, lithium raw material, and lanthanum raw material.

A lithium-lanthanum-titanium oxide sintered material has a lithium ion conductivity 3.010.sup.4 Scm.sup.1 or more at a measuring temperature of 27 C., the material is described by one of general formulas (1-a)La.sub.xLi.sub.2-3xTiO.sub.3-aSrTiO.sub.3, (1-a)La.sub.xLi.sub.2-3xTiO.sub.3-aLa.sub.0.5K.sub.0.5TiO.sub.3, La.sub.xLi.sub.2-3xTi.sub.1-aM.sub.aO.sub.3-a, and Sr.sub.x-1.5aLa.sub.aLi.sub.1.5-2xTi.sub.0.5Ta.sub.0.5O.sub.3 (0.55x0.59, 0a0.2, M=at least one of Al, Fe and Ga), and concentration of S is 1500 ppm or less. The material is obtained by sintering raw material powder mixture having S content amount of 2000 ppm or less in the entirety of raw material powders for mixture, that is, titanium raw material, lithium raw material, and lanthanum raw material.

A method includes the following steps: a) the production of a slip including more than 4% and less than 50% of ceramic particles and including: b) a first particulate fraction including of orientable particles having a median length L50 and representing more than 1% of the ceramic particles, and c) a second particulate fraction having a median length D50 at least ten times shorter than L50 and representing more than 1% of the ceramic particles, the first and second particulate fractions together representing more than 80% of all of the ceramic particles, in volume percentages based on the total quantity of ceramic particles; d) oriented freezing of the slip by moving a solidification front at a lower speed than the speed of encapsulation of the ceramic particles; e) elimination of the crystals of the solidified liquid phase of the block; and f) optionally sintering.

A piezoelectric ceramic composition contains a perovskite composition which is represented by (Pba.Math.Rex){Zr.sub.b.Math.Ti.sub.c, .Math.(Ni.sub.1/3Nb.sub.2/3).sub.d.Math.(Zn.sub.1/3Nb.sub.2/3).sub.e}O.sub.3 (wherein Re represents La and/or Nd, and a-e and x satisfy the following conditions 0.95a1.05, 0x0.05, 0.35b0.45, 0.35c0.45, 0<d0.10, 0.07e0.20 and b+c+d+e=1) and 0.05-0.3% by mass of an Ag component in terms of oxides relative to the perovskite composition.

A piezoelectric ceramic composition contains a perovskite composition which is represented by (Pba.Math.Rex){Zr.sub.b.Math.Ti.sub.c, .Math.(Ni.sub.1/3Nb.sub.2/3).sub.d.Math.(Zn.sub.1/3Nb.sub.2/3).sub.e}O.sub.3 (wherein Re represents La and/or Nd, and a-e and x satisfy the following conditions 0.95a1.05, 0x0.05, 0.35b0.45, 0.35c0.45, 0<d0.10, 0.07e0.20 and b+c+d+e=1) and 0.05-0.3% by mass of an Ag component in terms of oxides relative to the perovskite composition.

The present invention generally relates to high frequency piezoelectric crystal composites, devices, and method for manufacturing the same. In adaptive embodiments an improved imaging device, particularly a medical imaging device or a distance imaging device, for high frequency (>20 MHz) applications involving an imaging transducer assembly is coupled to a signal imagery processor. Additionally, the proposed invention presents a system for photolithography based micro-machined piezoelectric crystal composites and their uses resulting in improved performance parameters.

The present invention generally relates to high frequency piezoelectric crystal composites, devices, and method for manufacturing the same. In adaptive embodiments an improved imaging device, particularly a medical imaging device or a distance imaging device, for high frequency (>20 MHz) applications involving an imaging transducer assembly is coupled to a signal imagery processor. Additionally, the proposed invention presents a system for photolithography based micro-machined piezoelectric crystal composites and their uses resulting in improved performance parameters.