NEW METAL CATHODE

摘要

PURPOSE: A new metal cathode is provided to achieve improved electron emission capability and useful life of the cathode, while lowering the temperature of generating alkali earth metals. CONSTITUTION: A metal cathode comprises an alloy containing a platinum(Pt) and a barium(Ba); and a metal film layer formed on the alloy and made of one or more refractory metals selected from a group consisting of W, Mo, Nb, lr, Os, Rh and Ta. The metal film layer is formed by sintering a metal powder. Alternatively, the metal cathode comprises an alloy containing a platinum(Pt) and a barium(Ba); a first metal film layer formed on the alloy and made of one or more refractory metals selected from a group consisting of W, Mo, Nb, lr, Os, Rh and Ta; and a second metal film layer formed on the first metal film layer, and which contains a platinum-based metal or a rare earth metal.