Study on preparation and emission properties of nano-composite W–La2O3 material

Abstract: This paper describes the preparation of nano-composite W–La2O3 material by freeze-drying and spark plasma sintering (SPS). The thermionic electron emission capability and surface properties of this material have been investigated. The surface compositions and depth profiles of the prepared material were checked “in situ” by means of AES from 298K to 1573K. Nano-composite W–La2O3 material exhibits good electron emission performance: a saturated emission current density of 1.46Acm−2 can be reached at 1673K with a corresponding work function of 2.79eV. The surface analysis results showed that the good emission capability might be related to an about 10nm surface layer contained excess La caused by diffusion of La from bulk material to the surface. [Copyright &y& Elsevier]