Open AccessTHEORY OF THERMIONIC EMISSION (I)——A CRITICISM OF THE SEMI-CONDUCTOR MODEL OF THE OXIDE-COATED CATHODE
Author(s) -
Zhang En-Qiu
Publication year - 1974
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.23.43
Subject(s) - thermionic emission , materials science , cathode , coating , oxide , barium , conductor , barium oxide , hot cathode , optoelectronics , atomic physics , electron , composite material , physics , chemistry , quantum mechanics , metallurgy
For over twenty years, in the course of our work on the oxide-coated cathodes, we have frequently come across many phenomena which can not be explained by the semi-conductor theory. This has led us to re-examine carefully most of the parameters, such as work functions, electrical conductivities, spectral absorption, concentration of excess barium, lattice structure,surface energy states, distribution of potentials in the coating, comparsion of thin film emission to coating emission, non-uniformity of emission, flicker noise, instability of impulse current, sparking etc. All these show that the oxide-coated cathode is not an n-type semi-conductor with excess barium as donor. A preliminary theory of surface emission centers which can explain many phenomena in the oxidecoated cathode is proposed.