A novel approach to synthesis of scandia-doped tungsten nano-particles for high-current-density cathode applications

A novel synthesis approach for scandia-doped tungsten nano-powder using a sol-gel method is developed. It involves dissolving tungsten oxide at 300 degrees C in the presence of a mixture of nitric acid, citric acid and ammonia. The dissolved tungsten oxide reacts with an aqueous solution of scandium nitrate in the liquid-liquid phase, which results in the homogeneous mixing of tungsten and scandium particles. A spherical shape particle was obtained due to the dissolving of tungsten oxide in the solution. Citric acid enhances the mixing of ions at the atomic scale, which affects the hydrolysis reactions and leads to the formation of the phase pure nano-particle. The synthesized nano-powder was characterized by SEM (Scanning Electron Microscopy), EDS (Energy-dispersive X-ray spectroscopy), TEM (Transmission Electron Microscopy), and XRD (X-ray Diffraction) analyses. The spherical morphology was observed via a SEM analysis and a narrow particle size distribution was noted by means of a TEM analysis. The XRD analysis of the powder showed the complete formation of the phase pure nano-particle with an average diameter of 50 nm without any contamination by other materials. (C) 2012 Elsevier Ltd. All rights reserved.