Preparation and characterization of impregnated Y2O3-W Matrix Scandate Cathode

Impregnated Y₂O₃ Doped Tungsten Matrix Scandate Cathode was prepared by impregnating Y₂O₃-W matrix with barium-aluminum-scandate. The zero current density J₀ of the cathode at 900^oC_b has reached 14.63A/cm² and secondary emission yield δ is 3.51 after being optimally activated, both higher than the emission performances of Ba-W dispenser cathode. Auger electron spectroscopy result indicates that Sc, Ba and O diffuses from the interior porous body to surface simultaneously to form a “Ba-Sc-O” active substance layer, which lowers the work function of the cathode, and the increase of Y₂O₃ content will contribute to the formation of n-type semiconductor, which enhances the electric conductivity of the cathode, thus the emission performance of the cathode has been improved.