Current—Voltage Characteristics by Image Photometry in a Field-Ion Microscope
- 1 July 1966
- journal article
- research article
- Published by AIP Publishing in Journal of Applied Physics
- Vol. 37 (8), 3065-3070
- https://doi.org/10.1063/1.1703163
Abstract
Current—voltage characteristics of a FIM were determined indirectly through total imagephotometry in order to avoid known difficulties with ion current measurements. Relative phosphor screen efficiencies as a function of ion energy were calibrated separately. The total ion current under isothermal conditions is found to depend more sensitively upon the temperature than the T −1 power predicted by the present theory. The total ion current remarkably depends also on the tip temperature when the gas temperature is kept constant. Both temperature effects indicate that only a fraction of the gas molecules attracted to the tip by polarization contributes to the ion current. From the emitter cone‐angle dependence of the slope in the imaging range of the log I—log V plot and from the time‐lag effect after changing the emitter temperature it is concluded that the initial arrival of molecules at the emitter shank contributes significantly to the image gas supply. Imagephotometry can be used as a simple means to monitor the tip temperature with sufficient accuracy for most practical purposes.Keywords
This publication has 8 references indexed in Scilit:
- Gas-Surface Interactions and Field-Ion Microscopy of Nonrefractory MetalsJournal of Applied Physics, 1965
- Measurement of the Energy Distribution in Field IonizationThe Journal of Chemical Physics, 1964
- Current-voltage characteristics of the helium field-ion microscopePhilosophical Magazine, 1963
- Occurrence of H3+ in the Field Ionization of HydrogenThe Journal of Chemical Physics, 1962
- Mobility and Adsorption of Hydrogen on TungstenThe Journal of Chemical Physics, 1957
- Field Ionization of Gases at a Metal Surface and the Resolution of the Field Ion MicroscopePhysical Review B, 1956
- Thermal Accommodation Coefficient of Helium on a Bare Tungsten SurfaceThe Journal of Chemical Physics, 1955
- The adsorption of hydrogen on tungstenProceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1935