A co-assembly method for synthesizing inverse photonic structures is described. The method includes combining an onium compound with a sol-gel precursor to form metal oxide (MO) nanocrystals, where each MO nanocrystal has crystalline and amorphous content. The MO nanocrystals are combined with templating particles to form a suspension. A solvent is evaporated from the suspension to form an intermediate or compound product, which then undergoes calcination to produce an inverse structure.

Fabricating a layer including lithium lanthanum zirconate (Li.sub.7La.sub.3Zr.sub.2O.sub.12) layer includes forming a slurry including lanthanum zirconate (La.sub.2Zr.sub.2O.sub.7) nanocrystals, a lithium precursor, and a lanthanum precursor in stoichiometric amounts to yield a dispersion including lithium, lanthanum, and zirconium. In some cases, the dispersion includes lithium, lanthanum, and zirconium in a molar ratio of 7:3:2. In certain cases, the slurry includes excess lithium. The slurry is dispensed onto a substrate and dried. The dried slurry is calcined to yield the layer including lithium lanthanum zirconate.

According to one embodiment, an electrode material is provided. The electrode material includes active material particle containing: a niobium-titanium composite oxide having an average composition in which a molar ratio of niobium to titanium (M.sub.Nb/M.sub.Ti) is greater than 2; and at least one element A selected from the group consisting of potassium, iron and phosphorus. The active material particle contain the element A at a concentration in the range of 100 ppm to 2000 ppm.

Focus is on zinc oxide itself, which is a base material for a zinc oxide varistor (laminated varistor), wherein specified quantities of additives are added to a zinc oxide powder having a crystallite size of 20 to 50 nm, grain diameter of 15 to 60 nm found using the specific surface area BET method, untamped density of 0.38 to 0.50 g/cm.sup.3, and tap density of 0.50 to 1.00 g/cm.sup.3. This allows securing of uniformity, high compactness, and high electrical conductivity of a zinc oxide sintered body, and provision of a zinc oxide varistor having high surge resistance.

Focusing on zinc oxide itself, which is a main raw material for a zinc oxide varistor (laminated varistor), a predetermined amount of additive is added to a zinc oxide powder having crystallite size of 20 to 100 nm, particle diameter of 20 to 110 nm found using a specific area BET method, untamped density of 0.60 g/cm.sup.3 or greater, and tap density of 0.80 g/cm.sup.3 or greater. This allows a zinc oxide sintered body to secure uniformity, high density, and high electric conductivity, resulting in a zinc oxide varistor with high surge resistance, capable of downsizing and cost reduction. Moreover, addition of aluminum (Al), as a donor element, to the zinc oxide powder allows control of sintered grain size in conformity with the aluminum added amount and baking temperature, and also allows adjustment of varistor voltage, etc.

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.

A powder for coating or sintering has a peak assigned to cubic Y.sub.3Al.sub.5O.sub.12 and a peak assigned to orthorhombic YAlO.sub.3 exhibited in X-ray diffractometry, and the intensity ratio of the peak assigned to the (112) plane of the orthorhombic YAlO.sub.3 to the peak assigned to the (420) plane of the cubic Y.sub.3Al.sub.5O.sub.12 is at least 0.01 and less than 1. Alternatively, a powder for coating or sintering includes a composite oxide of yttrium and aluminum, and the volume of pores with a pore size of from 0.1 to 1 μm of the powder is at least 0.16 mL/g. It is preferable that, in X-ray diffractometry using CuKα radiation with a scan range of 2θ=20° to 60°, a peak assigned to the cubic Y.sub.3Al.sub.5O.sub.12 is a peak that shows the highest peak intensity.

The present application discloses a method for preparing an indium phosphide (InP) nanocrystal by using a novel phosphorus precursor as a raw material, and an InP nanocrystal having different wavelengths prepared by the method. The preparation method of the InP nanocrystal includes a step of: using M-(O—C≡P).sub.n as one of reaction precursors, where, M is a metal element, and n is a valence state of the M element. In this present application, M-(O—C≡P).sub.n serves as one of reaction precursors; due to that the metal element M and the element P are from the same reaction precursor, a nanocrystal of a nanocrystal core containing In, P and a metal element M can be prepared.

Provided are a method for producing calcium carbonate having a controlled size and a method for growing crystals in order to produce calcium carbonate having a controlled size. A method for producing a calcium carbonate comprises the steps of reducing the pH of an aqueous calcium carbonate dispersion to 9.0 or less and then increasing the pH of the aqueous calcium carbonate dispersion to grow calcium carbonate particles.

This invention relates to a process for manufacturing lithium nickel cobalt oxide-based cathode compounds for lithium ion secondary batteries. As part of this process, nickel, cobalt, and optionally manganese-bearing precursor compounds are lithiated and sintered at a high temperature. When cooled down, a high cooling rate will benefit the throughput of the process and the economics. It has however been found that the cooling rate should not exceed 10° C./min in what has been determined to be a critical temperature domain, ranging from 700° C. to 550° C.