Abstract: Disclosed is a TiO2 nano particle exhibiting a strongly activated catalyst function. The TiO2 nano particle is created by a step of mixing Ti powder and metal powder M (M is Ni, Cr, Pt, Rh, Ru or Cu), a step of generating heat plasma, and a step of supplying a mixture of the titanium powder and the metal powder to the heat plasma using an inert gas as a carrier gas and supplying oxygen gas to the heat plasma. The created TiO2 nano particle is injected with a metal and/or a metal oxide MxOy (M is Ni, Cr, Pt, Rh, Ru or Cu, x=1, 2, 3 . . . and y=0, 1, 2 . . . ), thereby exhibiting high photocatalytic activity.

Abstract: An intermetallic compound such as Nb.sub.3 Al exhibits the phenomenon of self-disintegration, when hydrogen is adsorbed in the intermetallic compound. This self-disintegration is used for the pulverization of the intermetallic compound material. The material is autogeneously pulverized into very fine particles only by adjusting an atmosphere to which the material is exposed, since the pulverizing reaction occurs between hydrogen existent in the atmosphere and the active surface of the intermetallic compound. The pulverized intermetallic compound having irregular shapes and large specific surface area is useful in various technical fields, e.g. as a superconductive material, a heat-resistant material, a magnetic body or a hydrogen-absorbing material.

Abstract: An aluminum nitride-based sintered product can be produced at a relatively low heating temperature by mixing at least 20% by weight of ultrafine aluminum powder having an average size of not exceeding 0.5 .mu.m with other powdery raw material, compression molding the resultant powdery mixture, and heating the molded article under a nitrogen atmosphere at a heating temperature ranging from 600.degree. to 800.degree. C. to nitride the ultrafine aluminum powder, whereupon the heat of nitridation is utilized to sinter the molded article.

Abstract: A process for producing ultrafine particles of a ceramic, which comprises heating a ceramic having substantially the same components as the final ultrafine ceramic particles, a metal constituting the metal component of the final ultrafine ceramic particles, a mixture of said ceramic with said metal or carbon, or a mixture of said metal with carbon by an arc plasma or a high frequency induction plasma generated in hydrogen, nitrogen, oxygen, a gaseous mixture of hydrogen and nitrogen, or a gaseous mixture of nitrogen and oxygen.

Abstract: A process for producing a mixed ultrafine powder, which comprises reacting at least two metals or ceramics in the molten state with hydrogen, nitrogen, oxygen, a mixture of hydrogen and nitrogen or a mixture of nitrogen and oxygen. Each said gas or gaseous mixture being activated with a hot plasma, in an atmosphere of hydrogen gas, nitrogen gas, oxygen gas, a gaseous mixture of hydrogen and nitrogen, a gaseous mixture of nitrogen and oxygen, or a gaseous mixture of any of said gases with an inert gas under a pressure of 50 torr to 3 atmospheres to form ultrafine particles of said at least two metals or ceramics afloat in the atmospheric gas, and thereafter mixing the floating ultrafine particles of the metals or ceramics by a gas current.

Abstract: A process for producing ultrafine particles of a ceramic, which comprises heating a ceramic having substantially the same components as the final ultrafine ceramic particles, a metal constituting the metal component of the final ultrafine ceramic particles, a mixture of said ceramic with said metal or carbon, or a mixture of said metal with carbon by an arc plasma or a high frequency induction plasma generated in hydrogen, nitrogen, oxygen, a gaseous mixture of hydrogen and nitrogen, or a gaseous mixture of nitrogen and oxygen.

Abstract: An apparatus for producing a particulate metal or alloy having a diameter of less than 5 microns by the reaction of a molten metal or alloy with activated hydrogen. The apparatus has (1) a metal melting hearth for melting a starting metal or alloy placed thereon and supporting the molten metal or alloy, (2) a discharge electrode positioned above, and opposite to, the metal or alloy placed on the melting hearth, (3) a closed vessel for containing the melting hearth and the discharge electrode, and (4) a gas inlet port in the wall of the closed vessel for introducing hydrogen or a hydrogen-containing gas into the vessel.

Abstract: A process for producing fine particles of a metal or alloy, which comprises contacting a molten metal or alloy with activated hydrogen gas thereby to release fine particles of the metal or alloy having a diameter of less than 10 microns from the molten metal or alloy.