Influence of Sharpness of Single Crystalline LaB₆ Cone on Field Emission Characteristics: A CST Simulation Study

The field emission of single crystalline LaB₆ tip was mathematically modeled with atruncated cone capped with a hemisphere, theoretically analyzed in Fowler-Nordheim equation, and numerically simulated with CST software. The impact of the cone-angle and spherical radius of the LaB₆ tipon the field emission behavior was investigated. The simulated results show that the tip radius significantly affects the field emission behavior. For example, as the tip radius decreases, the field emission current increased, simply because of the intensifying emission field.The conical-shaped emission electron beam spreads out from the tip apex. With a cone angle of 40°, a height of 2 mm and a hemisphere radius of 0. 1 μm, the optimized total emission current was 25. 5 μA ata field of 7. 22 × 10⁷ V/cm.We suggest that the simulated results may be of some technological interest in application of LaB₆ emitter.