Silver-metal oxide composite material and process for producing the same

The present invention relates to a silver-metal oxide mixed material comprising a silver-metal oxide mixed material comprising a silver matrix, a) from 1 to 20 weight percent, in terms of elemental metal, of a oxide of at least one element selected from the group consisting of Sn, Cd, Zn and In and, optionally, (b) from 0.01 to 8 weight percent, in terms of elemental metal, of an oxide of at least one element selected from the group consisting of Mg, Zr, Ca, Al, Ce, Cr, Mn and Ti and / or (c) from 0.01 to 8 weight percent, in terms of elemental metal, of an oxide of at least one element selected from the group consisting of Sb, Bi and metals of the iron family; the oxide of element (a) and, when present, the oxide of element (b) and / or the oxide of element (c) being dispersed as fine particles with a particle size not greater than about 0.1 or evenly through the silver matrix from the surface to the center of it and being linked to the silver matrix without leaving space between the oxides and the silver matrix.