Abstract: An extremely long-life, highly reproducible cathode is produced by preparing a porous sintered metal matrix, impregnating the matrix with a reagent containing a transition metal to modify the surface structure of the matrix, and then impregnating the surface-modified metal matrix with a barium-containing reagent to produce a cathode structure in which barium atoms are held in a metal-metal interaction with the transition metals and the surface of the matrix. In a preferred embodiment, the transition metal oxide is TiO.sub.2. This produces a barium/transition metal oxide surface structure which permits cathode operating temperatures on the order of 650 degrees C. The barium is stable and is retained on the surface of the metal matrix, so further dispensing is not required.