Nanosize structures composed of valve metals and valve metal suboxides and process for producing them

Abstract

A strip-like or sheet-like valve metal or valve metal suboxide structure which has a transverse dimension of from 5 to 100 nm.

1 .- 14 . (canceled) 
     
     
         15 . A strip-like or sheet-like valve metal or valve metal suboxide structure which comprises a transverse dimension of from 5 to 100 nm. 
     
     
         16 . The valve metal or valve metal suboxide structure according to  claim 15  having a sheet- or layer-like primary structure in the form of powders. 
     
     
         17 . The valve metal or valve metal suboxide structure according to  claim 15  in the form of a surface strip structure. 
     
     
         18 . The valve metal or valve metal suboxide structure according to  claim 17  in the form of foils or wires having strips having a width of from 5 to 100 nm and a strip spacing of from one to 2 times the strip width. 
     
     
         19 . The valve metal or valve metal suboxide structure according to  claim 15 , wherein the strips or lamellae are aligned parallel in groups. 
     
     
         20 . The valve metal or valve metal suboxide structure according to  claim 15 , wherein the transverse dimension or strip width is from 8 to 50 nm. 
     
     
         21 . The valve metal or valve metal suboxide structure according to  claim 15  comprising Ti, Zr, V, Nb, Ta, Mo, W, Hf or Al or alloys thereof. 
     
     
         22 . The valve metal or valve metal suboxide structure according to  claim 15  comprising Nb or Ta or alloys thereof. 
     
     
         23 . The valve metal suboxide structure according to  claim 15  having the formula NbO x  where 0.7<x<1.3. 
     
     
         24 . The valve metal or valve metal suboxide structure according to  claim 15 , having a content of at least one reducing metal in an amount of from 10 to 500 ppm. 
     
     
         25 . A process for the reduction of the valve metal oxides by means of the vapor of reducing metals at a temperature sufficient for reduction to form lamellar nanosize structures, wherein the reduced valve metal oxide is frozen before thermal decomposition of the lamellar structure and transformation into coarsened structures. 
     
     
         26 . The process according to  claim 25 , wherein the reduction is carried out at an inert gas pressure of less than 0.2 bar and a vapor pressure of the reducing metal of from 10 −2  to 0.4 bar. 
     
     
         27 . The process according to  claim 25 , wherein the reduction product is cooled to below 100° C. within a few minutes immediately after the reduction is complete. 
     
     
         28 . The process according to  claim 25 , wherein the reducing metal is Li, Al, Mg or Ca or a mixture thereof. 
     
     
         29 . The process according to  claim 25 , wherein the reducing metal is Mg. 
     
     
         30 . The process according to  claim 25 , wherein oxides of Al, Hf, Ti, Zr, V, Nb, Ta, Mo and/or W or mixed oxides thereof, are used as oxides to be reduced. 
     
     
         31 . The process according to  claim 25 , wherein oxides of Nb or Ta or mixed oxides thereof are used as oxides to be reduced.