A process for producing a particulate TiO.sub.2 includes supplementing metatitanic acid with an alkali compound in a quantity of 1200 ppm to 2400 ppm of alkali, with a phosphorus compound in a quantity of 0.1 wt.-% to 0.3 wt.-% by weight of P, expressed as phosphorus, and with an aluminum compound in a quantity of 1 ppm to 1000 ppm of Al, expressed as Al, to obtain a mixture. The quantity of the alkali compound, of the phosphorus compound, and of the aluminum compound are with respect to the TiO.sub.2 content. The mixture is calcined at a constant temperature of 940° C. to 1020° C. until a numerical fraction X.sub.50 of TiO.sub.2 has a primary crystallite size of at least 200 nm, to obtain a calcined mixture. The calcined mixture is cooled to obtain a cooled calcined mixture. The cooled calcined mixture is grinded to obtain the particulate TiO.sub.2.

Particles with suitable properties may be generated using systems and methods provided herein. The particles may include carbon particles.

Provided is a method of producing fine particulate barium calcium titanate in which calcium forms a homogeneous solid solution. The present invention relates to a method of producing a perovskite compound represented by the following formula (1):

Ba.sub.(1-x)A.sub.xTiO.sub.3  (1)

wherein A represents Ca or Sr, and x is a number satisfying 0.00<x≤0.30,

the method including: a first step of acid washing barium titanate to provide barium titanate having a ratio of barium element to titanium element of lower than 1.00; a second step of mixing the barium titanate obtained in the first step and a calcium salt or a strontium salt and drying the mixture to provide a dry mixture; and a third step of heating the dry mixture obtained in the second step.

A perovskite-type composite oxide powder is a perovskite-type composite oxide powder represented by a general formula ABO.sub.3-δ (where δ represents an amount of deficiency of oxygen and 0≤δ<1), an element contained in an A site is La, elements contained in a B site are Co and Ni and a crystallite size determined by a Williamson-Hall method is equal to or greater than 20 nm and equal to or less than 100 nm. In this way, when the perovskite-type composite oxide powder is used as an air electrode material for a fuel cell, an air electrode in which the resistance thereof is low and the conductivity thereof is high can be obtained.

Nanocomposite silicon and carbon compositions. These compositions can be made from polymer derived ceramics, and in particular, polysilocarb precursors. The nanocomposite can have non-voids or be nano-void free and can form larger macro-structures and macro-composite structures. The nanocomposite can contain free carbon domains in an amorphous SiOC matrix.

In an aspect, a Co.sub.2Z ferrite has the formula: (Ba.sub.1-xSr.sub.x).sub.3Co.sub.2+yM.sub.yFe.sub.24-2y-zO.sub.41. M is at least one of Mo, Ir, or Ru. The variable x can be 0 to 0.8, or 0.1 to 0.8. The variable y can be 0 to 0.8, or 0.01 to 0.8. The variable z can be −2 to 2. The Co.sub.2Z ferrite can have an average grain size of 5 to 100 nanometers, or 30 to 80, or 10 to 40 nanometers as measured using at least one of transmission electron microscopy, field emission scanning electron microscopy, or x-ray diffraction.

A barium titanate fiber is useful as a filler for a polymer composite piezoelectric body, a polymer composite piezoelectric body has high piezoelectric properties, and a piezoelectric element utilizes the polymer composite piezoelectric body. In the barium titanate fiber, the molar ratio of barium atoms to titanium atoms (Ba/Ti ratio) falls within the range of 1.01 to 1.04. The polymer composite piezoelectric body includes a resin composition containing the barium titanate fiber and a polymer. The piezoelectric element including an electrically conductive layer on one surface or both surfaces of the polymer composite piezoelectric body.

A positive electrode active material includes a lithium transition metal oxide, which is in the form of a secondary particle formed by aggregation of primary particles and is represented by Formula 1, wherein the lithium transition metal oxide has a crystalline size of 160 nm or less and an average particle diameter of the primary particle of 0.6 μm or more. A preparation method thereof is also provided.

The present disclosure relates to a solid electrolyte containing a halide-based nanocomposite, a method for preparing the same and an all-solid-state battery including the solid electrolyte. Halide-based nanocomposites were prepared by the mechanochemical reaction of a lithium oxide precursor, a lithium halide precursor, and a metal halide in order to improve the low ion conductivity and large interfacial resistance of the existing halide-based solid electrolyte. Furthermore, it is possible to provide superior atmospheric stability, improve ion conductivity through activation of interfacial conduction and, at the same time, significantly improve the interfacial stability with a sulfide-based solid electrolyte and high-voltage cycle stability.

The present invention relates to a method of controlling the arrangement of building block nanocrystals in iron oxide mesocrystals by controlling the type of surface ligand, the method including mixing an iron ion precursor and a surface ligand. The present invention can provide nanoparticles having different magnetic properties by controlling the crystallographic arrangement of building block nanocrystals in mesocrystals according to surface ligands.