A composite thermionic cathode consisting of 12CaO·7Al 2O3 (C12A7) electride and metallic Ti (70 : 30 vol %) was fabricated as an electron emitter, and the thermionic electron emission properties were evaluated. A high emission current density of ∼1:4mAcm -2 was achieved at 700 °C with an electric field of 4:0 × 104 Vcm-1. The work function evaluated from the Richardson-Dushman equation was 2:1 ± 0:3 eV, which coincides with the value for pure C12A7 electride and is lower than that for LaB6. Unlike the pure material, the composite has ohmic contact with metallic materials, and can be heated directly by electrical current.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)