Variation with Temperature of the Work Function of Oxide-Coated Platinum
- 1 September 1926
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 28 (3) , 521-523
- https://doi.org/10.1103/physrev.28.521
Abstract
A series of tests was made with standard Western Electric VT2 vacuum tubes, in which the filament was held at a higher temperature for a period of five minutes and then returned to a lower reading temperature (950°C) and the electron current measured with a plate potential of 110 volts. It was found that the previous heating of the filament caused a temporary increase in the electron current over the normal value for that temperature, and that this effect increased with temperature up to about 1130°C, after which point it began to fall off. The results of another series of tests indicate that positive ion emission from the filament begins at a temperature somewhat above that which produced maximum electron current. These results are in agreement with the theory that the thermionic activity of oxide-coated platinum filaments is probably due to a film of metallic barium and strontium produced by reduction of the oxides.Keywords
This publication has 3 references indexed in Scilit:
- Thermionic Phenomena Caused by Vapors of Rubidium and PotassiumPhysical Review B, 1926
- Thermionic effects caused by vapours of alkali metalsProceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, 1925
- Thermionic Effects Caused by Alkali Vapors in Vacuum TubesScience, 1923