Preparation of the REO-Mo secondary emitter with sub-micro structure by SPS method

Millimeter wave magnetron has exhibited promising prospect in its application. Due to intensive electron back-bombardment in millimeter wave magnetron, Ba-W dispenser cathodes may not be ideal long-acting electron source in such devices. The traditional Th-W cathode encounters fatal shortcoming of radioactivity. REO-Mo metal-ceramic cathode is one of the hopeful cathodes for millimeter wave magnetron because of their shortage of natural radioactivity background and lower cost than recently developed Ir-La alloy cathode. Investigations from Wang showed the low susceptivity of REO-Mo metal ceramic cathodes to electron bombardment and the dependence of secondary emission property on the distribution of different ingredient and microstructure of materials. Therefore, in this work, attempts are made to prepare the REO-Mo metal ceramic cathodes with fine sub-micro structure on the basis of precursor rare oxide doped molybdenum powder synthesized by a sol-gel and two-step method.