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 0.05≤x≤3; 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 0.1≤y≤3, and z satisfies 0.15≤z≤6.

A method foe 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.

The present disclosure relates to the methods of preparing two-dimensional arrays of nanocrystalline metal carbide and metal nitride compositions and the compositions and devices derived from these methods and compositions.

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.

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.

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.

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.

A ceramic powder containing at least one of a nitride and a carbonitride of a metal element as a major component, the metal element being one or more elements selected from the group consisting of a group 4 element, a group 5 element and a group 6 element, the ceramic powder having particles having an average particle size of 5 m or less, and an oxygen content of 0.3% by mass or less.

A niobium compound and a method of forming a thin film using the niobium compound, the compound being represented by the following General formula I:

##STR00001##

wherein, in General formula I, R.sup.1, R.sup.4, R.sup.5, R.sup.6, R.sup.7, and R.sup.8 are each independently a hydrogen atom, a C1-C6 linear or branched alkyl group or a C3-C6 cyclic hydrocarbon group, at least one of R.sup.4, R.sup.5, R.sup.6, R.sup.7, and R.sup.8 being a C1-C6 linear or branched alkyl group, and R.sup.2 and R.sup.3 are each independently a hydrogen atom, a halogen atom, a C1-C6 linear or branched alkyl group, or a C3-C6 cyclic hydrocarbon group.

Provided are methods of stabilizing MXene compositions using polyanionic salts so as to reduce the oxidation of the MXenes. Also provided are stabilized MXene compositions.