Effect of ZrH2 Doping on Electron Emission Performance of Rare Earth Tungsten Electrode

In order to explore the effect of ZrH2 on the electron emission performance of rare earth tungsten electrodes (W-La-Y), different proportions of ZrH2 were added to rare earth tungsten in this study, and samples of three proportions were obtained by ball milling and vacuum hot-pressing sintering. The electron emission performance, phase evolution and surface valence state of the samples were analyzed, respectively. The test results of electrode emission performance show that increasing the mass fraction of ZrH2 in the range of 0% to 0.1% can continuously improve the electrode emission performance. At 1600 °C, 0.1% ZrH2 can increase the zero-field current emission density from 0.36 to 0.90 A/cm2. X-ray diffraction (XRD), the comprehensive thermalgravimetric and differential thermal analysis (TG-DTA) and X-ray photoelectron spectroscopy (XPS) results showed that the ZH2 added to rare earth tungsten electrodes would react with impurity oxygen in the electrode and consume impurity oxygen, thus reducing the inhibitory effect of impurity oxygen on the electron emission of the electrode and improving its electron emission performance.