A battery comprising an acidified metal oxide (“AMO”) material, preferably in monodisperse nanoparticulate form 20 nm or less in size, having a pH <7 when suspended in a 5 wt % aqueous solution and a Hammett function H.sub.0 >−12, at least on its surface.

A battery comprising an acidified metal oxide (“AMO”) material, preferably in monodisperse nanoparticulate form 20 nm or less in size, having a pH <7 when suspended in a 5 wt % aqueous solution and a Hammett function H.sub.0 >−12, at least on its surface.

Coated zirconia fine particle containing a zirconia fine particle and a coating layer coating the surface of the fine particle. The coating layer includes one or more metal elements selected from Mg, Ca, Al and rare-earth elements, and the coated zirconia fine particle has an average particle size of 3 to 100 nm and a specific surface area of 20 to 500 m.sup.2/g.

Coated zirconia fine particle containing a zirconia fine particle and a coating layer coating the surface of the fine particle. The coating layer includes one or more metal elements selected from Mg, Ca, Al and rare-earth elements, and the coated zirconia fine particle has an average particle size of 3 to 100 nm and a specific surface area of 20 to 500 m.sup.2/g.

An object of the present invention is to provide a hydrogen permeable material having excellent hydrogen permeability. Another object of the present invention is to provide a composite member and a fuel cell including the hydrogen permeable material. The hydrogen permeable material comprises a perovskite type compound represented by the following general formula (1a). In another embodiment, the hydrogen permeable material comprises a hydrogen-containing perovskite type compound, which is the perovskite type compound represented by the general formula (1a) with introduced hydride ion (H.sup.−). Wherein M is at least one alkaline earth metal selected from the group consisting of Ba, Sr and Ca, x is a numerical value of 0 or more and 0.3 or less, y is a numerical value of more than 0 and 0.75 or less, w is a value at which an average valence of In is +1.0 or more and +2.5 or less, and y≥w.

M.sub.1-xZr.sub.1-yIn.sub.yO.sub.3-x-0.5y-2  (1a)

An object of the present invention is to provide a hydrogen permeable material having excellent hydrogen permeability. Another object of the present invention is to provide a composite member and a fuel cell including the hydrogen permeable material. The hydrogen permeable material comprises a perovskite type compound represented by the following general formula (1a). In another embodiment, the hydrogen permeable material comprises a hydrogen-containing perovskite type compound, which is the perovskite type compound represented by the general formula (1a) with introduced hydride ion (H.sup.−). Wherein M is at least one alkaline earth metal selected from the group consisting of Ba, Sr and Ca, x is a numerical value of 0 or more and 0.3 or less, y is a numerical value of more than 0 and 0.75 or less, w is a value at which an average valence of In is +1.0 or more and +2.5 or less, and y≥w.

M.sub.1-xZr.sub.1-yIn.sub.yO.sub.3-x-0.5y-2  (1a)

Methods are provided herein for forming transition metal oxide thin films, preferably Group IVB metal oxide thin films, by atomic layer deposition. The metal oxide thin films can be deposited at high temperatures using metalorganic reactants. Metalorganic reactants comprising two ligands, at least one of which is a cycloheptatriene or cycloheptatrienyl (CHT) ligand are used in some embodiments. The metal oxide thin films can be used, for example, as dielectric oxides in transistors, flash devices, capacitors, integrated circuits, and other semiconductor applications.

Methods are provided herein for forming transition metal oxide thin films, preferably Group IVB metal oxide thin films, by atomic layer deposition. The metal oxide thin films can be deposited at high temperatures using metalorganic reactants. Metalorganic reactants comprising two ligands, at least one of which is a cycloheptatriene or cycloheptatrienyl (CHT) ligand are used in some embodiments. The metal oxide thin films can be used, for example, as dielectric oxides in transistors, flash devices, capacitors, integrated circuits, and other semiconductor applications.

Provided is a method for producing a porous metal oxide. The method includes: preparing a slurry by mixing a metal source, a pore forming agent and an aqueous solvent; drying the slurry to obtain a metal oxide precursor; and sintering the metal oxide precursor to generate a porous metal oxide. The metal source is an organometallic compound or hydrolyzate thereof containing a metal that makes up the porous metal oxide; the pore forming agent is an inorganic compound that generates a gas by decomposing at a temperature equal to or lower than a temperature at which the metal oxide precursor is sintered; and the slurry is prepared using 50 parts by weight or more of the pore forming agent with respect to 100 parts by weight of the metal source.

Provided is a method for producing a porous metal oxide. The method includes: preparing a slurry by mixing a metal source, a pore forming agent and an aqueous solvent; drying the slurry to obtain a metal oxide precursor; and sintering the metal oxide precursor to generate a porous metal oxide. The metal source is an organometallic compound or hydrolyzate thereof containing a metal that makes up the porous metal oxide; the pore forming agent is an inorganic compound that generates a gas by decomposing at a temperature equal to or lower than a temperature at which the metal oxide precursor is sintered; and the slurry is prepared using 50 parts by weight or more of the pore forming agent with respect to 100 parts by weight of the metal source.