Scandate cathode work function measurements at elevated temperature

The work function of a scandate cathode prepared using the L-S technique, and measured in vacuum at elevated temperature, is presented here. The scandate cathode had undergone emission testing and displayed excellent emission behavior in a close-spaced diode testing apparatus, before the work function measurements were carried out. The work function at room temperature was measured to be 4.81 eV, and this value tended to decrease as the temperature was raised to 800°C, with a minimum value existing at 600°C. The implications for this behavior are also discussed.