| 摘要 |
PURPOSE: To improve cathode efficiency at low temperatures by comprising a base member of a highly porous sintered metal, a transition metal oxide bonded to surface atoms of the metallic base member, and an enlarged effective area, and forming with barium which forms a metal-to-metal band with a transition metal oxide. CONSTITUTION: In a cathode 10, a support plate 12 supports a sintered metallic base member 14, made of W and WO3 to which a cathode current is applied. The metallic base member has an extremely irregular top surface 16 for increasing its effective surface area. The base member 14 has porous 18, opening to a top surface 16. A heater 20 is disposed under the support plate 12, to heat the cathode 10 up to its working temperature. The crystal structure of the metamorphic sintered metal support member 14 on the surface 16 is such that transition metal oxide molecules 22 bonded to oxygen atoms on the surface oxide, formed on the tungsten atoms of the base member 14. A barium layer 24 has a barium atom bonded to two oxygen atoms of titania TiO2 . This provides a high cathode efficiency and enables working at a relatively low temperature. |
