| 摘要 |
PURPOSE:To obtain a cathode structure with high current density and long life without causing the deterioration of the initial electron emission capability by combining grains coprecipitated with scandium and grains not containing scandium to form an alkaline earth metal oxide layer. CONSTITUTION:An alkaline earth metal oxide layer containing Ba, e.g., alkaline earth metal carbonate layer 2, is deposited and formed on the surface of an Ni substrate metal 1. Grains coprecipitated with Sc[(Ba.Sr.Ca.Sc)CO3] 3 and grains not containing Sc[(Ba.Sr.Ca)CO3] 4 are combined for this carbonate layer 2, one or more kinds of the Sc content of the grains 3 coprecipitated with Sc are contained in the combined material, and the quantity of Sc is set to the range of 0.01-0.1wt.% of the total quantity of the carbonate layer 2. The substrate metal 1 deposited with the carbonate layer 2 is fixed to one end of a cathode support tube 5, and a spiral heater is buried in an insulator (not shown in the figure) in the support tube 5. This cathode structure body is assembled in a color cathode-ray tube to activate the decomposition of the exhaust gas. |
