Abstract: [Summary] Provided is a cathode active material for a lithium secondary battery having a layered rock salt structure, including a secondary grain formed of a large number of primary grains each having an average grain size of 0.01 ?m or more and 5 ?m or less, in which the secondary grain has the following characteristics: a (003) plane orientation degree of 60% or more; an average grain size of 1 ?m or more and 100 ?m or less; an aspect ratio of 1.0 or more and less than 2; a voidage of 3% or more and 30% or less; an average pore size of 0.1 ?m or more and 5 ?m or less; and a value obtained by dividing the average grain size of each of the primary grains by the average pore size of 0.1 or more and 5 or less.

Abstract: A crystallographically-oriented ceramic containing Pb and in which piezoelectric/electrostrictive properties can be enhanced. Using a raw material having Pb(Zr1-xTiX)O3 as a main component, a ceramic sheet was formed with a thickness of 15 ?m or less. In this material, grains were allowed to grow into an anisotropic shape, and crystal grains with specific crystal planes being aligned were produced. A non-oriented raw material having Pb(Zr1-xTiX)O3 as a main component and the crystal grains were mixed, and shaping was performed so that crystal grains were oriented in a predetermined direction. The shaped body was fired. In the resulting ceramic, the degree of orientation was high at 50% or more. It is possible to enhance the degree of orientation using, as crystal nuclei, a ceramic sheet which can have the same composition as that of the crystallographically-oriented ceramic. Therefore, production can be performed without adding an unnecessary element, for example, for orienting crystals.

Abstract: An actuator includes a fired ceramic substrate having a space opened downward, a first electrode formed on the upper surface of the fired ceramic substrate above the space, a piezoelectric/electrostrictive body formed on the first electrode so that the volume changes with input and output of electric power, and a second electrode formed on the piezoelectric/electrostrictive body. The piezoelectric/electrostrictive body is composed of Pb(Zr1-xTix)O3 or (Li, Na, K) (Nb, Ta)O3 as a main component and contains crystals oriented along the direction of an electric field. In the actuator, the degree of orientation of the piezoelectric/electrostrictive body can be increased regardless of the orientation of the substrate on which the piezoelectric/electrostrictive body is formed.

Abstract: A (Li, Na, K)(Nb, Ta)O3 based piezoelectric/electrostrictive porcelain composition obtained by adding a slight amount of a Mn compound to a perovskite type oxide containing Li, Na and K as A-site elements and contains at least Nb out of Nb and Ta as B-site elements, where a ratio of a total number of atoms of the A-site elements to a total number of atoms of the B-site elements is not smaller than 1. A composition of the perovskite type oxide as a principal component is represented by a general formula: {Liy(Na1-xKx)1-y}a(Nb1-zTaz)O3. The A/B ratio “a” preferably satisfies 1<a?1.05. The Mn compound as an accessory component is desirably added such that the added amount is not more than 3 parts by mol in terms of Mn atom with respect to 100 parts by mol of said perovskite type oxide.

Abstract: A (Li, Na, K)(Nb, Ta)O3-based piezoelectric/electrostrictive ceramic composition having a large field-induced distortion during application of a high electric field is provided. After synthesizing a perovskite oxide containing Li (lithium), Na (sodium) and K (potassium) as A-site elements and containing at least Nb (niobium) out of the Nb and Ta (tantalum) as B-site elements, a ratio of total number of atoms of the A-site elements to total number of atoms of the B-site elements being higher than 1, a Bi (bismuth) compound is added to the perovskite oxide and the perovskite oxide is reacted with the Bi compound. An addition amount of the Bi compound with respect to 100 molar parts of the perovskite oxide is preferably equal to or greater than 0.01 molar part and equal to or smaller than 0.1 molar part in terms of Bi atoms.

Abstract: An actuator includes a first electrode disposed on the top surface of a ceramic substrate (for example, zirconium oxide), a piezoelectric/electrostrictive substance disposed on the first electrode, and a second electrode disposed on the piezoelectric/electrostrictive substance, wherein the input of an electric power alters the volume of the piezoelectric/electrostrictive substance. The piezoelectric/electrostrictive substance contains a plurality of crystal grains that have a wavy structure composed of wavy grain boundaries including concave portions and convex portions. The crystal grains contain ABO3 as the main component. The A site is Pb, and the B site contains such an amount of M that M becomes excessive after the piezoelectric/electrostrictive substance is formed (wherein M is at least one element selected from Mg, Ni, and Zn). The crystal grains of the piezoelectric/electrostrictive substance are oriented in the electric field direction, independently of the orientation of the substrate.

Abstract: The production method of the present invention includes (A) a raw material preparation step of preparing a raw material mixture containing at least a manganese compound; (B) a forming step of forming the raw material mixture prepared through the raw material preparation step into a compact having a longitudinal size L and a maximum size R as measured in a direction perpendicular to the longitudinal direction (i.e., in a thickness direction) such that L/R is 3 or more; (C) a firing step of firing the compact obtained through the forming step; and (D) a crushing step of crushing the fired compact obtained through the firing step.

Abstract: The production method of the present invention includes a raw material preparation step of preparing a raw material mixture; a firing step of firing the raw material mixture prepared through the raw material preparation step; and a crushing step of crushing the fired compact obtained through the firing step, wherein the raw material mixture contains a main raw material containing at least a manganese compound, and a seed crystal having a spinel-type crystal structure.

Abstract: The production method of the present invention includes (A) a forming step of forming into a sheet-like compact a raw material containing at least a manganese compound and not containing a lithium compound; (B) a first firing step of firing the sheet-like compact formed through the forming step; and (C) a second firing step of firing a mixture of the fired compact obtained through the first firing step and a lithium compound at a temperature lower than the firing temperature employed in the first firing step.

Abstract: A positive electrode active material containing a large number of crystal grains which contain, by 70 areal % or more, primary particles of non-octahedral shape, having particle diameters of 5 to 20 ?m, and composed of lithium manganate of spinel structure containing lithium and manganese as the constituent elements.

Abstract: A positive electrode active material comprising a large number of crystal grains composed of lithium manganate of spinel structure, wherein the large number of crystal grains contain primary particles of 3 to 20 ?m in particle diameter by 70 areal % or more relative to all the crystal grains, the primary particles contain a component having a rectangular plane, and the ratio of the total area of all the rectangular planes to the total surface area of the primary particles is 0.5 to 5%.

Abstract: A positive electrode active material having a specific surface area of 0.1 to 0.5 m2/g, which contains a large number of crystal grains containing primary particles of 5 to 20 ?m in particle diameter, composed of lithium manganate of spinel structure containing lithium and manganese as the constituent elements, and a bismuth compound containing bismuth, wherein the proportion of the primary particles contained in the large number of crystal grains is 70 areal % or more and the proportion of the bismuth contained in the bismuth compound is 0.005 to 0.5 mol % relative to the manganese contained in the lithium manganate.

Abstract: A positive electrode active material having an average from 1 ?m or lager to smaller than 5 ?m and containing a large number of crystal grains being composed of lithium manganate of spinel structure containing lithium and manganese as constituent elements, whose crystallite size is 500 to 1,500 nm in powder X-ray diffraction pattern, and whose value of a lattice strain (?) of 0.05×10?3 to 0.9×10?3 in powder X-ray diffraction pattern, and whose D50/DBET ratio is 1 to 4 wherein the D50 (?m) is the median diameter of the positive electrode active material and the DBET (?m) is calculated from the BET specific surface area by using the following general formula (1). DBET=6/(d×S)??(1) [Wherein d is the true density (g/cm3) of the positive electrode active material powder and S is BET specific surface area (m2/g) in the general formula (1).

Abstract: A manufacturing method of the present invention includes (a) a material preparation step of preparing a material containing lithium, manganese, and bismuth, and (b) a firing step of firing the material prepared by the material preparation step at a temperature of 830° C. to 1,000° C. In the material preparation step, the material is prepared such that the residual amount of bismuth in spinel-type lithium manganate yielded by the firing step is 0.01 mol % or less with respect to manganese.

Abstract: A piezoelectric/electrostrictive device which exhibits an excellent piezoelectric characteristic and which has only a small dependence on a temperature is provided. The piezoelectric/electrostrictive device includes a piezoelectric/electrostrictive portion made of a piezoelectric ceramic, and electrodes electrically connected to the piezoelectric/electrostrictive portion. The piezoelectric ceramic reversibly transits to a tetragonal phase and an orthorhombic phase at a phase transition point as a boundary. The piezoelectric/electrostrictive portion is formed by a polarization treatment performed under the conditions that a treatment temperature ranges from a first temperature which exceeds the phase transition point of the piezoelectric ceramic to a second temperature which is 50° C. higher than the first temperature.

Abstract: An actuator includes a first electrode disposed on the top surface of a ceramic substrate (for example, zirconium oxide), a piezoelectric/electrostrictive substance disposed on the first electrode, and a second electrode disposed on the piezoelectric/electrostrictive substance, wherein the input of an electric power alters the volume of the piezoelectric/electrostrictive substance. The piezoelectric/electrostrictive substance contains a plurality of crystal grains that have a wavy structure composed of wavy grain boundaries including concave portions and convex portions. The crystal grains contain ABO3 as the main component. The A site is Pb, and the B site contains such an amount of M that M becomes excessive after the piezoelectric/electrostrictive substance is formed (wherein M is at least one element selected from Mg, Ni, and Zn). The crystal grains of the piezoelectric/electrostrictive substance are oriented in the electric field direction, independently of the orientation of the substrate.

Abstract: A (Li, Na, K)(Nb, Ta)O3-based piezoelectric/electrostrictive ceramic composition having a large field-induced distortion during application of a high electric field is provided. After synthesizing a perovskite oxide containing Li (lithium), Na (sodium) and K (potassium) as A-site elements and containing at least Nb (niobium) out of the Nb and Ta (tantalum) as B-site elements, a ratio of total number of atoms of the A-site elements to total number of atoms of B-site elements being higher than 1, a Bi (bismuth) compound is added to the perovskite oxide and the perovskite oxide is reacted with the Bi compound. An addition amount of the Bi compound with respect to 100 molar parts of the perovskite oxide is preferably equal to or greater than 0.01 molar part and equal to or smaller than 0.1 molar part in terms of Bi atoms.

Abstract: A plate-like polycrystalline particle is produced by forming inorganic particles into a freestanding shaped body, firing the shaped body, and crushing and classifying the fired shaped body. The inorganic particles contain as the main component an oxide that has a general formula of ABO3 and that satisfies a×Pb(M1/3,Nb2/3)O3+b×PbTiO3+c×PbZrO3+z×MO (wherein a+b+c=1, and M denotes at least one element selected from Mg, Ni, and Zn), wherein z is in the range of 0.002?z?0.42. The oxide contains a predetermined excessive amount of MO (M denotes at least one element selected from Mg, Ni, and Zn) such that the plate-like polycrystalline particle contains an excessive amount of MO. The plate-like polycrystalline particle contains a plurality of crystal grains that have a wavy structure composed of wavy grain boundaries. The plate-like polycrystalline particle is easily crushed at the grain boundaries and has a high degree of orientation.

Abstract: An actuator includes a fired ceramic substrate having a space opened downward, a first electrode formed on the upper surface of the fired ceramic substrate above the space, a piezoelectric/electrostrictive body formed on the first electrode so that the volume changes with input and output of electric power, and a second electrode formed on the piezoelectric/electrostrictive body. The piezoelectric/electrostrictive body is composed of Pb(Zr1-xTix)O3 or (Li, Na, K) (Nb, Ta)O3 as a main component and contains crystals oriented along the direction of an electric field. In the actuator, the degree of orientation of the piezoelectric/electrostrictive body can be increased regardless of the orientation of the substrate on which the piezoelectric/electrostrictive body is formed.

Abstract: A monomorph type piezoelectric/electrostrictive device includes a piezoelectric/electrostrictive body, which is composed of a non-lead based piezoelectric/electrostrictive crystalline body containing at least Nb, Ta, and one or more types of alkali metal element, which has a cubic crystal structure at a temperature higher than the phase transition point and at least any one of tetragonal and orthorhombic crystal structures at a temperature lower than the phase transition point, and which is curved to a large extent by a polarization treatment to take on a curved shape at a temperature lower than the phase transition point without application of a voltage after the polarization treatment. In the polarization treatment, an electric field is increased at a speed of from 0.1 (kV/mm)/sec or more to 5 (kV/mm)/sec or less, with applying the maximum electric field of from 2 kV/mm or more to 1.0 kV/mm or less.