A positive-electrode active material contains a lithium composite oxide containing manganese. The crystal structure of the lithium composite oxide belongs to a space group Fd-3m. The integrated intensity ratio I.sub.(111)/I.sub.(400) of a first peak I.sub.(111) on the (111) plane to a second peak I.sub.(400) on the (400) plane in an XRD pattern of the lithium composite oxide satisfies 0.05I.sub.(111)/I.sub.(400)0.90.

A method of preparing cerium boride powder, according to the present invention, includes a first step for generating mixed powder by mixing at least one selected from among cerium chloride (CeCl.sub.3) powder and cerium oxide (CeO.sub.2) powder, at least one selected from among magnesium hydride (MgH.sub.2) powder and magnesium (Mg) powder, and boron oxide (B.sub.2O.sub.3) powder, a second step for generating composite powder including cerium boride (Ce.sub.xB.sub.y) and at least one selected from among magnesium oxide (MgO) and magnesium chloride (MgCl.sub.2), by causing reaction in the mixed powder at room temperature based on a ball milling process, and a third step for selectively depositing cerium boride powder by dispersing the composite powder in a solution.

Heat ray shielding fine particles contain calcium lanthanum boride fine particles represented by a general formula Ca.sub.xLa.sub.1-xB.sub.m, a shape of each fine particle of the calcium lanthanum boride fine particles satisfies at least one of the following: 1) when scattering intensity of the calcium lanthanum boride fine particles diluted and dispersed in a solvent is measured using small-angle X-ray scattering, value Ve of a slope of a straight line is 3.8Ve1.5, 2) the particle shape is a flat cylindrical shape, or a flat spheroidal (wherein a length of a long axis is d and a length of a short axis is h) shape, with a value of aspect ratio d/h being 1.5d/h20.

Heat ray shielding fine particles contain calcium lanthanum boride fine particles represented by a general formula Ca.sub.xLa.sub.1-xB.sub.m, a shape of each fine particle of the calcium lanthanum boride fine particles satisfies at least one of the following: 1) when scattering intensity of the calcium lanthanum boride fine particles diluted and dispersed in a solvent is measured using small-angle X-ray scattering, value Ve of a slope of a straight line is 3.8Ve1.5, 2) the particle shape is a flat cylindrical shape, or a flat spheroidal (wherein a length of a long axis is d and a length of a short axis is h) shape, with a value of aspect ratio d/h being 1.5d/h20.

A positive-electrode active material contains a lithium composite oxide containing at least one selected from the group consisting of F, Cl, N, and S. The crystal structure of the lithium composite oxide belongs to a space group C2/m. An XRD pattern of the lithium composite oxide comprises a first peak within the first range of 44 degrees to 46 degrees of a diffraction angle 2 and a second peak within the second range of 18 degrees to 20 degrees of the diffraction angle 2. The ratio of the second integrated intensity of the second peak to the first integrated intensity of the first peak is within a range of 0.05 to 0.90.

Articles comprising a boron allotrope and an organic compound having a lateral interface one with the other, together with method(s) of preparation of such articles.

Articles comprising a boron allotrope and an organic compound having a lateral interface one with the other, together with method(s) of preparation of such articles.

Methods for providing new transparent near infrared absorptive fine particles having a wide range of near infrared absorption, which are an assembly of hexaboride fine particles, where when a particle shape of the number of particles contained in the assembly is approximately regarded as a spheroid body, there are 20% or more and less than 80% of particles having an aspect ratio [(long axis length)/(short axis length)] of 1.5 or more and less than 5.0, and there are 20% or more and less than 80% of particles having an aspect ratio of 5.0 or more and less than 20.0.

A positive-electrode active material contains a lithium composite oxide, wherein the lithium composite oxide is a multiphase mixture including a first phase, of which a crystal structure belongs to a space group Fm-3m, and a second phase, of which a crystal structure belongs to a space group Fd-3m; and in an XRD pattern of the lithium composite oxide, the integrated intensity ratio I.sub.(18-20)/I.sub.(43-46) of a first maximum peak I.sub.(18-20) within a first range of 18 degrees to 20 degrees at a diffraction angle 2 to a second maximum peak I.sub.(43-46) within a second range of 43 degrees to 46 degrees at the diffraction angle 2 satisfies 0.05I.sub.(18-20)/I.sub.(43-46)0.90.

To provide a method for producing lanthanum hexaboride-containing composite particles which are capable of forming a formed product having sufficiently high transparency and which are excellent in weather resistance, by a simple operation without calcination treatment at high temperature, and a method for producing a formed product using it.

A method for producing composite particles, which comprises: reacting at least one silica precursor selected from the group consisting of a tetraalkoxysilane, its hydrolysate and its condensate, in the presence of lanthanum hexaboride particles, a volatile base, water and an organic solvent to obtain a first reaction mixture, and reacting the first reaction mixture with at least one silicon compound selected from the group consisting of an amino-modified silicone, an alkylsilane and an aminosilane, or the silicon compound and the silica precursor added, to obtain a second reaction mixture containing lanthanum hexaboride-containing composite particles.