| 摘要 |
PURPOSE:To improve the initial emission characteristic and prevent the generation of an intermediate layer at the boundary surface between a substrate metal and an electron emitting material layer by depositing the electron emitting material layer of the specific mixed salt on the substrate metal face. CONSTITUTION:An electron emitting material layer 20 made of the coprecipitated mixed salt 12 of barium salt and rare earth metal salt of 20-45mol% is deposited on a substrate metal 1 of a cathode for an electron tube. The initial emission characteristic is improved due to the use of this mixed salt, and the intermediate layer of a composite oxide prohibiting the current flow is prevented from being generated on the boundary surface between the metal 1 and the layer 20 at the time of high-current density operation. As a result, the stable emission characteristic is maintained for a long time, and the reliability is improved. Scandium salt is preferable for the rare earth metal salt, and nickel is preferable for the substrate metal. |
