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.

An X-ray diffractometrically single-phase lithium titanium phosphate can be obtained by an industrially advantageous method. Provided is a method for producing the lithium titanium phosphate having a NASICON structure represented by the following general formula (1): Li.sub.1+xM.sub.x(Ti.sub.1−yA.sub.y).sub.2−x(PO.sub.4).sub.3 (1), and provided is a method comprising a first step of preparing a raw material mixed slurry (1) comprising, at least, titanium dioxide, phosphoric acid and a surfactant, a second step of heat treating the raw material mixed slurry (1) to obtain a raw material heat-treated slurry (2), a third step of mixing the raw material heat-treated slurry (2) with a lithium source to obtain a lithium-containing raw material heat-treated slurry (3), a fourth step of subjecting the lithium-containing raw material heat-treated slurry (3) to a spray drying treatment to obtain a reaction precursor containing, at least, Ti, P and Li, and a fifth step of firing the reaction precursor.

An oxide includes a compound represented by Formula 1, a compound represented by Formula 2, or a combination thereof:

Li.sub.1−x+y−zTa.sub.2−xM.sub.xP.sub.1−yQ.sub.yO.sub.8−zX.sub.z  Formula 1

wherein, in Formula 1, M is an element having an oxidation number of 5+ or 6+, Q is an element having an oxidation number of 4+, X is a halogen atom, a pseudohalogen, or a combination thereof,
0≤x<0.6, 0≤y<1, and 0≤z<1, wherein x and y are not 0 at the same time,

Li.sub.1−x+yTa.sub.2−xM.sub.xP.sub.1−yQ.sub.yO.sub.8.zLiX  Formula 2

wherein, in Formula 2, M is an element having an oxidation number of 5+ or 6+, Q is an element having an oxidation number of 4+, X is a halogen atom, a pseudohalogen or a combination thereof, 0≤x<0.6, 0≤y<1, and 0≤z<1, wherein x and y are not 0 at the same time, and
wherein in Formulas 1 and 2, M, Q, x, y, and z are independently selected.

An object of the present invention is to provide zirconium oxide nanoparticles that have excellent dispersibility in a polar solvent and are capable of increasing a core concentration in a dispersion liquid. Zirconium oxide nanoparticles according to the present invention are coated with at least one compound selected from the group consisting of R.sup.1—COOH, (R.sup.1O).sub.3-n—P(O)—(OH).sub.n, (R.sup.1).sub.3-n—P(O)—(OH).sub.n, (R.sup.1O)—S(O)(O)—(OH), R.sup.1—S(O)(O)—(OH), and (R.sup.1).sub.4-m—Si(R.sup.4).sub.m, wherein R.sup.1 represents a group comprising a carbon atom and at least one element selected from the group consisting of an oxygen atom, a nitrogen atom, and a sulfur atom, and having the total number of carbon atoms, oxygen atoms, nitrogen atoms, and sulfur atoms of 8 or less; R.sup.4 represents a halogen atom or —OR.sup.2, and R.sup.2 represents a hydrogen atom or an alkyl group; and n represents 1 or 2, and m represents an integer of 1 to 3.

Provided are: a nonaqueous electrolyte secondary battery positive electrode active material that has high crystallinity, that causes less amount of Mn deposition on a negative electrode, and that can form a secondary battery having excellent cycle characteristics; and a nonaqueous electrolyte secondary battery using the nonaqueous electrolyte secondary battery positive electrode active material. The nonaqueous electrolyte secondary battery positive electrode active material according to the present invention is formed of a lithium-manganese-nickel complex oxide including a spinel-type crystal structure, wherein the lithium-manganese-nickel complex oxide has a crystallite diameter not smaller than 1000 Å and is formed of primary particles that have a polyhedron shape having more than eight surfaces. The proportion of ungrown particles not having the polyhedron shape of the primary particles in the lithium-manganese-nickel complex oxide is preferably not higher than 5%.

A method for forming lithium metal oxides comprised of Ni, Mn and Co useful for making lithium ion batteries comprises providing precursor particulates of Ni and Co that are of a particular size that allows the formation of improved lithium metal oxides. The method allows the formation of lithium metal oxides having improved safety while retaining good capacity and rate capability. In particular, the method allows for the formation of lithium metal oxide where the primary particle surface Mn/Ni ratio is greater than the bulk Mn/Ni. Likewise the method allows the formation of lithium metal oxides with secondary particles having much higher densities allowing for higher cathode densities and battery capacities while retaining good capacity and rate performance.

A positive electrode active material for a non-aqueous electrolyte secondary battery achieves high output characteristics and battery capacity, and allows a high electrode density to be achieved in the case of using the material for a positive electrode of a battery; and a non-aqueous electrolyte secondary battery uses the positive electrode active material, thereby achieving a high output with a high capacity. Prepared is a nickel composite hydroxide including plate-shaped secondary particles aggregated with overlaps between plate surfaces of multiple plate-shaped primary particles, where shapes projected from directions perpendicular to the plate surfaces of the plate-shaped primary particles are any plane projection shape of spherical, elliptical, oblong, and massive shapes, and the secondary particles have an aspect ratio of 3 to 20, and a volume average particle size (Mv) of 4 μm to 20 μm measured by a laser diffraction scattering method.

Process for making lithiated transition metal oxide particles comprising the steps of: (a) Providing a particulate mixed transition metal precursor comprising Ni and at least one transition metal selected from Co and Mn, and, optionally, at least one further metal selected from Ti, Zr, Mo, W, Al, Mg, Nb, and Ta, (b) mixing said precursor with at least one compound of lithium and at least el one processing additive comprising potassium, (c) treating the mixture obtained according to step (b) at a temperature in the range of from 700 to 1,000° C.

A sintered material includes a cubic boron nitride, a zirconium-containing oxide, a zirconium-containing nitride, and an aluminum-containing oxide, wherein the zirconium-containing nitride includes both or one of ZrN and ZrON, and the aluminum-containing oxide includes a type Al.sub.2O.sub.3.

Described herein is a process for making a nickel composite hydroxide with a mean particle diameter d50 in the range from 3 to 20 μm including combining (a) an aqueous solution of water-soluble salts of nickel and of at least one of cobalt and manganese, and, optionally, at least one of Al, Mg, B, or transition metals other than nickel, cobalt, and manganese, (b) an aqueous solution of an alkali metal hydroxide and (c) an aqueous solution of alkali metal (bi)carbonate or ammonium (bi)carbonate in the molar ratio of 0.001:1 to 0.04:1, and, optionally, (d) an aqueous solution of alkali metal aluminate,
in a continuous stirred tank reactor or in a cascade of at least two continuous stirred tank reactors.