| 摘要 |
PURPOSE:To obtain the emission property being stable in a long period even in high current density operation by overlaying a mixture layer and an alkaline earth metallic oxide in order on a substrate. CONSTITUTION:The topside of the bottom of a substrate 1 whose main ingredient consists of nickel is covered with a mixture layer 4 which contains at least one kind among a scandium oxide, an aluminum oxide, and an aluminum nitride, and this layer 4 is covered with an electron emitter layer 5 which contains alkaline earth metallic oxide such as barium. Accordingly, by the interposition of the mixture layer 4, the heat conductivity at the bonding interface between the substrate and the emitter layer 5 is maintained stably, and the current density also improves. |
