Abstract: An oxide cathode is provided including a metal base, an electron emissive material layer formed on the metal base and having barium as a main component, a heater for heating the electron emissive material layer, and a Ba evaporation restraining layer having a thickness ranging from 10.ANG. to 10,000.ANG. and consisting of at least one titanium compound formed on the electron emissive material layer.

Abstract: An oxide cathode is provided including an electron emissive material layer including barium, a metal base, a sleeve and a heater, wherein the electron emissive material layer further includes 0.1 to 20 wt. % of tin or a tin compound, based on the total amount of the electron emissive material, and indium or an indium compound.

Abstract: A method for manufacturing a dispenser cathode is disclosed. The method includes a step of immersing, in an aqueous solution containing an aluminum compound, either (1) a powder mixture made by mixing metal powder selected from among Mo, Ta, W or alloys thereof with a carbonate selected form the group of Sr, Ba, Ca, or mixtures thereof or (2) a pellet of such a metal powder mixture formed into a desired shape, such that the aluminum ingredient in the aqueous solution can be impregnated into (1) the powder mixture or (2) the pellet. According to the present method, heat treatment at a temperature of over 1700.degree. C. is not required, unlike conventional methods where such high heat treatment is required. Therefore the decrease of electron releasing efficiency due to adverse reactions generated by the high temperature heat treatment of the prior art can be avoided.