A method and system for manufacturing a field emission cathode having enhanced electron emission properties. The field emission cathode is prepared by providing a field emission substrate, an alkali metal alloy is formed at and below the exposed surface of the substrate, and a surface layer of alkali metal atoms are formed on the exposed surface by Gibbsian diffusion segregation action. If the monolayer, or surface layer, is desorbed, the diffusion action reestablishes the alkali metal surface layer thereby providing a stable alkali metal layer and enhanced electron emission characteristics.