(57) A cathode subassembly for color CRTs is provided, which exhibits scarcely the degradation
of electron emission capability for at least ordinary lifetime of color CRTs even
at a high current density greater than 1 A/cm2 while it has an equivalent activation time and an equivalent operating temperature
to those of former oxide cathodes. The cathode subassembly is comprises (a) a porous
cathode pellet (11) formed by a sintered body containing Ni, scandium oxide (Sc2O3), and an electron-emissive material; the body being made by sintering a mixture of
a Ni powder, a scandium oxide (Sc2O3) powder, and an electron-emissive material powder using a HIP process; the pellet
having an electron emission surface; and (b) a pellet support (12) for supporting
the pellet; the support having a part in contact with the pellet; the part being made
of an alloy containing Ni as its main ingredient and at least one metal selected from
the group consisting of chromium (Cr), tantalum (Ta), molybdenum (Mo), zirconium (Zr),
tungsten (W), and cobalt (Co); the at least one metal selected from the group consisting
of Cr, Ta, Mo, Zr, W, and Co serving as a reducing agent for the electron-emissive
material. Preferably, the electron-emissive material is a carbonate generated by co-precipitation
of Ba, Sr, and Ca.
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