High quality, catalyst-free boron nitride nanotubes (BNNTs) that are long, flexible, have few wall molecules and few defects in the crystalline structure, can be efficiently produced by a process driven primarily by Direct Induction. Secondary Direct Induction coils, Direct Current heaters, lasers, and electric arcs can provide additional heating to tailor the processes and enhance the quality of the BNNTs while reducing impurities. Heating the initial boron feed stock to temperatures causing it to act as an electrical conductor can be achieved by including refractory metals in the initial boron feed stock, and providing additional heat via lasers or electric arcs. Direct Induction processes may be energy efficient and sustainable for indefinite period of time. Careful heat and gas flow profile management may be used to enhance production of high quality BNNT at significant production rates.

A continuous tubular reactor includes a rotary reaction tube having a reactant inlet and a product outlet, and including a ceramic; a heating device disposed outside the rotary reaction tube; and an angle adjuster adjusting an angle of a rotation axis of the rotary reaction tube. The angle of the rotation axis is 75 or less with respect to a horizontal surface.

A method for producing AlN crystals includes using at least one element, excluding Si, that satisfies a condition under which the element forms a compound with neither Al nor N or a condition under which the element forms a compound with any of Al and N provided that the standard free energy of formation of the compound is larger than that of AlN; melting a composition containing at least Al and the element; and reacting the Al vapor with nitrogen gas at a predetermined reaction temperature to produce AlN crystals.

Scintillator materials based on mixed garnet compositions, as well as corresponding methods and systems, are described.

A positive electrode active material includes a lithium transition metal oxide represented by Formula 1, wherein the lithium transition metal oxide includes a center portion having a layered structure and a surface portion having a secondary phase with a structure different from that of the center portion.

Li.sub.1a(Ni.sub.xCo.sub.yM.sup.1.sub.zM.sup.2.sub.w).sub.1aO.sub.2[Formula 1]

In Formula 1, 0a0.2, 0.6x1, 0y0.4, 0z0.4, and 0w0.1, M.sup.1 includes at least one selected from the group consisting of manganese (Mn) and aluminum (Al), and M.sup.2 includes at least one selected from the group consisting of zirconium (Zr), boron (B), tungsten (W), molybdenum (Mo), chromium (Cr), tantalum (Ta), niobium (Nb), magnesium (Mg), cerium (Ce), hafnium (Hf), lanthanum (La), titanium (Ti), strontium (Sr), barium (Ba), fluorine (F), phosphorus (P), sulfur (S), and yttrium (Y). A method of preparing the positive active material is also provided.

A modified boron nitride nanotube (BNNT) comprising pendant hydroxyl (OH) and amino (NH.sub.2) functional groups covalently bonded to a surface of the BNNT. Aqueous and organic solutions of these modified BNNTs are disclosed, along with methods of producing the same. The modified BNNTs and their solutions can be used to coat substrates and to make nanocomposites.

The present specification discloses a method for producing a hybrid structure which includes a first step of preparing a mesoporous silica mold; a second step of uniformly mixing and heating a metal chelate compound and the mold to obtain a precursor of the hybrid structure; and a third step of obtaining a hybrid structure by etching the precursor under acid conditions, and wherein the metal chelate compound includes one or more carbon atoms, one or more nitrogen atoms, and one or more metal atoms.

In order to provide a novel oriented apatite-type oxide ion conductor which can achieve an increase in area through suppression of crack generation and preferably can be manufactured more inexpensively by an uncomplicated process, an oriented apatite-type oxide ion conductor composed of a composite oxide represented by A.sub.9.33+x[T.sub.6yM.sub.y]O.sub.26.00+z A in the formula is one kind or two or more kinds of elements selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Be, Mg, Ca, Sr, and Ba. T in the formula is an element including Si, Ge, or both of them. M in the formula is one kind or two or more kinds of elements selected from the group consisting of B, Ge, Zn, Sn, W, and Mo.

A template-assisted method for the synthesis of 2D nanosheets comprises growing a 2D material on the surface of a nanoparticle substrate that acts as a template for nanosheet growth. The 2D nanosheets may then be released from the template surface, e.g. via chemical intercalation and exfoliation, purified, and the templates may be reused.

Provided is a high-density lithium-containing garnet crystal body. The lithium-containing garnet crystal body has a relative density of 99% or more, belongs to a tetragonal system, and has a garnet-related type structure. A method of producing a Li.sub.7La.sub.3Zr.sub.2O.sub.12 crystal, which is one example of this lithium-containing garnet crystal body, includes melting a portion of a rod-like raw material composed of polycrystalline Li.sub.7La.sub.3Zr.sub.2O.sub.12 belonging to a tetragonal system while rotating it on a plane perpendicular to the longer direction and moving the melted portion in the longer direction. The moving rate of the melted portion is preferably 8 mm/h or more but not more than 19 mm/h. The rotational speed of the raw material is preferably 30 rpm or more but not more than 60 rpm. By increasing the moving rate of the melted portion, decomposition of the raw material due to evaporation of lithium can be prevented and by increasing the rotational speed of the raw material, air bubbles can be removed.