Thermionic tungsten/scandate cathodes and method of making the same

摘要

A thermionic dispenser cathode having a refractory metal matrix with scandium and barium compounds in contact with the metal matrix and methods for forming the same. The invention utilizes atomic layer deposition (ALD) to form a nanoscale, uniform, conformal distribution of a scandium compound on tungsten surfaces and further utilizes in situ high pressure consolidation/impregnation to enhance impregnation of a BaO—CaO—Al₂O₃ based emissive mixture into the scandate-coated tungsten matrix or to sinter a tungsten/scandate/barium composite structure. The result is a tungsten-scandate thermionic cathode having improved emission.