Research on the nano-particle carbonates oxide cathode

In this paper, a research on the nano-particle carbonates oxide cathode for further enhancing the emission characteristics of the cathode was reported. Emission characteristics of the reservoir oxide cathode are mainly dependent upon the ratio of different ingredients of three kinds of alkaline earth carbonates (BaCO₃, SrCO₃ and CaCO₃) on the cathode surface and its micro-shape. The cathode has better emission characteristics when BaCO₃: SrCO₃: CaCO₃ mole ratio is (50%-58%): (38%-45%):(4%-8%). Different shape with same ingredient of the carbonate can affect the cathode emission current. The synthesizing method plays a key role in determining the shape of the carbonate. The investigations show that the shape of carbonates synthesized by gas-liquid method is affected by the temperature, the concentration and stirring speed. When stirring speed is less than 600r/min and the concentration is between 0.2mol/L and 0.3mol/L, the carbonates particle is tiny particle while the temperature is between 30°C and 40°C. And the carbonates particle becomes fine long needle while the temperature exceeds 70°C. Considering above all, a nano-particle triple carbonate with the diameter of 80 nm-100 nm by adjusting temperature, concentration and stirring speed in the synthesis processes was developed.