| 摘要 |
PURPOSE:To obtain the stable emission characteristic for a long time under the high current density by containing an alloy of 0.1-20wt% made of scandium, magnesium, and silicon in an electron emitting material layer. CONSTITUTION:An alloy of 0.1-20wt% made of scandium, magnesium, and silicon is contained in an electron emitting material layer 2a mainly composed of an alkaline earth metal oxide containing barium. An Sc diffusion layer is formed near the interface of a substrate 1, and a composite oxide layer containing the reducing element in the substrate 1 generated near the interface by this Sc diffusion layer when a cathode is operated is dissociated. A highly insulating composite oxide layer is thus prevented from being segregated on the interface. The sufficient emission characteristic under the high current density can be obtained accordingly. |
