Characterization of scandate cathode at different stages of processing

Characterization was performed on samples representing scandate cathodes at key stages of processing. This included the starting powders, sintered pellets, impregnated pellets and activated cathodes, with special emphasis on the impregnated state. It was observed that pores were occupied by scandia after the pressing and sintering stage, and were subsequently completely filled after the impregnation stage. Interestingly, streaks of scandium-containing phases were observed in the impregnated sample. Activated cathodes did not exhibit the expected morphology with highly faceted tungsten, which may be due to a high oxygen content that originated from the powder preparation process.