Study on rare earth oxide-molybdenum cermet cathode materials

The emission property of a new kind of rare earth oxide-molybdenum cermet cathode made by powder metallurgy has been studied in this paper. The experimental results show that adding either single rare earth oxides La2O3, Y2O3, and Gd2O3 or a mixture of these rare earth oxides into molybdenum can improve the secondary emission coefficient of the cathode. After La2O3-Y2O3-Gd2O3-Mo is activated at 1600 deg. C, the maximum secondary emission coefficient can be high to more than 3.0. This kind of cathode also shows good secondary emission stability during 1000 h of life experiment and capability of anti-exposure to atmosphere. The zero-field emission density of 0.12 A/cm2 is reached at 1470 deg. C