A slurry of a dispersion medium and rare earth oxide particles. The particles having a volume basis median particle size D50 of up to 50 nm. The rare earth oxide particles having a dispersity index S of up to 1, the dispersity index S being determined according to the formula (1):
(D90D10)/D50(1) wherein D10, D50 and D90 are cumulative 10%, 50% and 90% diameters in volume basis particle size distribution, respectively.

A slurry of a dispersion medium and rare earth oxide particles. The particles having a volume basis median particle size D50 of up to 50 nm. The rare earth oxide particles having a dispersity index S of up to 1, the dispersity index S being determined according to the formula (1):
(D90D10)/D50(1) wherein D10, D50 and D90 are cumulative 10%, 50% and 90% diameters in volume basis particle size distribution, respectively.

A solid electrolyte of the present disclosure contains Li, M, and X, and, in the solid electrolyte, the coefficient of variation of the M content is 10 or less, and the coefficient of variation of the X content is 15 or less. A method for producing a solid electrolyte according to the present disclosure includes (A) synthesizing a halide containing Li, M, and X, (B) pulverizing the halide, and (C) heat-treating the halide, and the (A), the (B), and the (C) are performed in this order. Here, M is at least one selected from the group consisting of metalloids and metal elements other than Li, and X is at least one selected from the group consisting of F, Cl, Br, and I.

A solid electrolyte of the present disclosure contains Li, M, and X, and, in the solid electrolyte, the coefficient of variation of the M content is 10 or less, and the coefficient of variation of the X content is 15 or less. A method for producing a solid electrolyte according to the present disclosure includes (A) synthesizing a halide containing Li, M, and X, (B) pulverizing the halide, and (C) heat-treating the halide, and the (A), the (B), and the (C) are performed in this order. Here, M is at least one selected from the group consisting of metalloids and metal elements other than Li, and X is at least one selected from the group consisting of F, Cl, Br, and I.

Provided herein are phosphors of the general molecular formula:
(A.sub.2-2xEu.sub.x)(Mg.sub.1-yCa.sub.y)PO.sub.4F
wherein the variables are as defined herein. Methods of producing the phosphors are also provided. In some aspects, the present disclosure provides light-emitting devices comprising these phosphors.

Provided herein are phosphors of the general molecular formula:
(A.sub.2-2xEu.sub.x)(Mg.sub.1-yCa.sub.y)PO.sub.4F
wherein the variables are as defined herein. Methods of producing the phosphors are also provided. In some aspects, the present disclosure provides light-emitting devices comprising these phosphors.

A method is provided for separating and/or purifying different metal oxalates by mixing the different metal oxalates in an aqueous solution comprising oxalic acid and an organic base so that at least one metal oxalate is soluble and at least another metal oxalate is not soluble. Different rare earth metal oxalates and/or transition metal oxalates can be separated.

The invention relates to a method for producing a scandium-containing concentrate from the wastes of alumina production and extracting high-purity scandium oxide from the same. Provided is a method for producing a scandium-containing concentrate from a red mud, wherein the Sc.sub.2O.sub.3 content therein is least of 15 wt. % (in terms of dry matter), the TiO.sub.2 content not more than 3 wt. % (in terms of dry matter), the ZrO.sub.2 content not more than 15 wt. % (in terms of dry matter), and wherein scandium in the concentrate is in form of a mixture of Sc(OH).sub.3 hydroxide with ScOHCO.sub.34H.sub.2O. Also provided is a method for producing high-purity scandium oxide, with a purity of approximately 99 wt. %.

The present disclosure provides for a method of obtaining metals from a source, including contacting the source with an ionic liquid in the absence of acid, thereby extracting the metals from the source and providing an ionic liquid extraction composition; and recovering the metals from the ionic liquid extraction composition, wherein the source includes coal, coal by-products, ore, tar, or electronic waste. Further, the present disclosure provides for a carbon material made by a process that includes contacting a source with an ionic liquid in the absence of acid, thereby extracting metals from the source and providing an ionic liquid extraction composition; and recovering the metals from the ionic liquid extraction composition, wherein the source includes coal, coal by-products, ore, tar, or electronic waste, further wherein the carbon material includes solids, liquids, carbon films, carbon fibers, carbon nanomaterials, or any combination thereof.

The present disclosure provides for a method of obtaining metals from a source, including contacting the source with an ionic liquid in the absence of acid, thereby extracting the metals from the source and providing an ionic liquid extraction composition; and recovering the metals from the ionic liquid extraction composition, wherein the source includes coal, coal by-products, ore, tar, or electronic waste. Further, the present disclosure provides for a carbon material made by a process that includes contacting a source with an ionic liquid in the absence of acid, thereby extracting metals from the source and providing an ionic liquid extraction composition; and recovering the metals from the ionic liquid extraction composition, wherein the source includes coal, coal by-products, ore, tar, or electronic waste, further wherein the carbon material includes solids, liquids, carbon films, carbon fibers, carbon nanomaterials, or any combination thereof.