Development of Nanocrystalline LaB6 Electron Emitters Processed Using Arc Thermal Plasma Route

Present article discusses the role of plasma parameters on the morphology of nanocrystalline powders of lanthanum hexaboride (LaB6) synthesized by arc plasma gas-phase condensation method. The nanocrystalline powders so obtained were used to fabricate pellet-shaped cathodes of 5 mm diameter and thickness of 1 mm. Moreover, thermal plasma plume was used for sintering the cathodes and achieve desired densification. Prior to fabrication of cathodes, the synthesized powders of LaB6 were characterized using X-ray diffraction, Raman spectroscopy, and transmission electron microscopy to investigate phase purity and morphological properties. Finally, an indigenously developed thermionic emission experimental set-up was used to record thermionic emission current obtained from LaB6 cathode at different temperatures. Richardson Dushman equation was used to find out the work function of the cathode under investigation.

Automated summary

This study synthesized LaB6 nanocrystalline powders using arc plasma gas-phase condensation method, fabricated pellet-shaped cathodes, and achieved densification through sintering with thermal plasma plume. The phase purity and morphological properties of the synthesized powders were characterized using X-ray diffraction, Raman spectroscopy, and transmission electron microscopy, and the work function of the cathode was calculated using Richardson Dushman equation based on thermionic emission current measurements at different temperatures.