High-performance Field Emission Rare Earth Tungsten Alloy Cathodes Dataest

Based on first-principles calculations using density functional theory, this study constructs atomic models of W cathode surfaces doped with different rare earth atoms. Using a (2×2×1) W(001) surface model, 1 ML of O atoms is adsorbed on the top site of the surface, followed by doping rare earth atoms (La, Ce, Y) into the W-O lattice vacancy sites. The work functions of the system with rare earth atom coverages of 0.5 ML and 1 ML were calculated. Through liquid phase synthesis, plasma discharge sintering, and heat treatment, nano-scale second-phase rare earth oxides (La₂O₃, CeO₂, Y₂O₃, etc.)–tungsten cathodes were produced. Different ignition experiments were designed to simulate various operating conditions. The cascade arc plasma source was used for mass-loss and lifetime prediction tests on the cathode materials. After testing, SEM and EDS microscopic characterizations of the cathode materials were conducted to analyze their composition, morphology, and elemental distribution.