Current Fluctuations in the Oxide Cathode

Abstract

DURING some work here on the relation between the conduction and emission mechanisms in the oxide cathode (assumed an excess electronic semi-conductor) we have come across slow but marked fluctuations in the values of both currents when these were measured simultaneously for certain values of the field applied to the anode. Further, over the range of temperature explored, a threshold at about l,100°K. was indicated, which is well above the temperature at which ‘p’ type conduction has been suspected; generally, the current fluctuations become more and more compensatory in the sense that an increase in one occurs simultaneously with a decrease in the other, till at l,250°K., the marked field periodicity shown in the diagram takes place. Above this temperature, the fluctuations are much larger for certain field values and the correlation less pronounced, but the general character of the form of the curves is maintained.