Development of Nano Materials for the Application in Cathode in High Power Microwave Tube Devices
In this research work, A dispenser cathode is made out of a porous tungsten matrix into which Ba-Ca-Aluminates are introduced through a process called impregnation. An addition of a small amount of Scandia (Sc2O3) to the impregnant results in more than ten-fold in emission. In this work an attempt has been made to synthesize Scandate material which is basically a composite of W doped mixed oxides of Sc, Ba, Ca, and Al in powder form prepared by commercial planetary ball mill (PBM) and subsequent making of Pellet using H2sintering. The nano sized Sc2O3 has been evidenced through XRD and TEM, which indicates the particle size in between 10-50 nm, also the nano crystallite nature of BaCaAl2O3 has been found from FE-SEM with particle size < 50 nm. The mixture composite of the said matrix after making pallet with the help of H2 sintering was found to be 96 % density, which is of required goal to make nano-scandate cathode for high current density application in microwave tube.