Provided herein is a method for preparing MXenes, such as Ti.sub.2CT.sub.x, Cr.sub.2CT.sub.x, and V.sub.2CT.sub.x, products prepared therefrom, and compositions and devices including the same.

A main object of the present disclosure is to provide an active material of which capacity properties are excellent. The present disclosure achieves the object by providing an active material to be used for a fluoride ion battery, the active material comprising: a composition represented by M.sup.1N.sub.x in which M.sup.1 is at least one kind of Cu, Ti, V, Cr, Fe, Mn, Co, Ni, Zn, Nb, In, Sn, Ta, W, and Bi, and x satisfies 0.05x3; or a composition represented by M.sup.2Ln.sub.yN.sub.z in which M.sup.2 is at least one kind of Cu, Ti, V, Cr, Fe, Mn, Co, Ni, Zn, Nb, In, Sn, Ta, W, and Bi, Ln is at least one kind of Sc, Y, and lanthanoid, y satisfies 0.1y3, and z satisfies 0.15z6.

In a vanadium nitride film formed on a surface of a base material, a ratio V [at %]/N [at %] between a vanadium element concentration and a nitrogen element concentration in the film is 1.08 or more and a chlorine element concentration in the film is 1 at % or more and 5 at %/or less.

A method for producing a transparent electrode for oxygen production having a Ta nitride layer on a transparent substrate, including: a step of forming a Ta nitride precursor layer on the transparent substrate; and a step of nitriding the Ta nitride precursor layer with a mixed gas containing ammonia and a carrier gas.

A process for manufacturing a compound in powder form, wherein said compound is the reaction product of (i) at least one metal and/or metalloid, and (ii) at least one further element that is more electronegative than the metal and/or metalloid, which process includes steps of: mixing at least one oxide of said at least one metal and/or metalloid with a reducing agent including Ca or Mg granules or powder, and/or calcium hydride or magnesium hydride in granule or powder form, to form a mixture; exposing the mixture to a source of said at least one further element; maintaining said mixture under a H.sub.2 atmosphere at a temperature of from 950 C. to 1500 C. for 1-10 hours; and, recovering said compound in powder form; wherein said at least one further element is selected from carbon, nitrogen, boron, silicon and mixtures thereof. A compound in powder form obtainable by such a process.

The present invention is directed to crystalline solids having an empirical formula of M.sub.2A.sub.2X, wherein M is at least one Group IIIB, IVB, VB, or VIB metal, preferably Cr, Hf, Sc, Ti, Mo, Nb, Ta, V, Zr, or a combination thereof; wherein A is Al, Ga, Ge, In, Pb, or Sn, or a combination thereof; and each X is C.sub.xN.sub.y, where x+y=1. In some particular embodiments, the crystalline composition has a unit cell stoichiometry of Mo.sub.2Ga.sub.2C.

A main object of the present disclosure is to provide an active material of which capacity properties are excellent. The present disclosure achieves the object by providing an active material to be used for a fluoride ion battery, the active material comprising: a composition represented by M.sup.1N.sub.X in which M.sup.1 is at least one kind of Cu, Ti, V, Cr, Fe, Mn, Co, Ni, Zn, Nb, In, Sn, Ta, W, and Bi, and x satisfies 0.05x3; or a composition represented by M.sup.2Ln.sub.yN.sub.z in which M.sup.2 is at least one kind of Cu, Ti, V, Cr, Fe, Mn, Co, Ni, Zn, Nb, In, Sn, Ta, W, and Bi, Ln is at least one kind of Sc, Y, and lanthanoid, y satisfies 0.1y3, and z satisfies 0.15z6.

A tantalum sputtering target, wherein, on a sputtering surface of the tantalum sputtering target, an orientation rate of a (200) plane exceeds 70%, an orientation rate of a (222) plane is 30% or less. By controlling the crystal orientation of the target, effects are yielded in that the discharge voltage of the tantalum sputtering target can be reduced so that plasma can be more easily generated, and the voltage drift during deposition can be suppressed.

A tantalum sputtering target, wherein, on a sputtering surface of the tantalum sputtering target, an average crystal grain size is 50 m or more and 150 m or less, and a variation in a crystal grain size is 30 m or less. A tantalum sputtering target, wherein, on a sputtering surface of the tantalum sputtering target, an orientation rate of a (200) plane exceeds 70%, an orientation rate of a (222) plane is 30% or less, an average crystal grain size is 50 m or more and 150 m or less, and a variation in a crystal grain size is 30 m or less. By controlling the crystal grain size of the target, or the crystal grain size and the crystal orientation of the target, effects are yielded in that the discharge voltage of the tantalum sputtering target can be reduced so that plasma can be more easily generated, and the voltage drift during deposition can be suppressed.

Disclosed is a composition having nanoparticles or particles of a refractory metal, a refractory metal hydride, a refractory metal carbide, a refractory metal nitride, or a refractory metal boride, an organic compound consisting of carbon and hydrogen, and a nitrogenous compound consisting of carbon, nitrogen, and hydrogen. The composition, optionally containing the nitrogenous compound, is milled, cured to form a thermoset, compacted into a geometric shape, and heated in a nitrogen atmosphere at a temperature that forms a nanoparticle composition comprising nanoparticles of metal nitride and optionally metal carbide. The nanoparticles have a uniform distribution of the nitride or carbide.