Thermal Desorption of Potassium from Clean and Sulfur Covered Nickel

• Authors: R. Błaszczyszyn , M. Błaszczyszynowa , W. Gubernator
• Languages of publication: EN

Abstracts

EN

Activation energy for thermal desorption of potassium from clean and sulfur covered surfaces of nickel was determined by means of the field emis­sion method. For the low potassium coverage limit (Θ_{K} ≈ 0.02) the desorp­tion was detected from the whole emitter surface in the temperature range of 825-1000 K for the atoms and of 725-825 K for the species of atoms and ions of the potassium. The activation energies of neutral desorption were found to be E^{a}_{Ni} = 3.8 eV for the clean nickel and E^{a}_{S/Ni} = 3.0 eV for the sulfur covered nickel, Θ_{s} ≈ 0.5. The activation energies for the desorption of the species of atoms and ions increased from E^{a+i}_{Ni} = 2.5 eV for the clean nickel to E^{a+i}_{S/Ni} = 2.9 eV for the sulfur covered nickel Θ_{s} ≈ 0.5. Also, a value of E^{a+i}_{S'/Ni} = 4.1 eV was found for a higher coverage of sulfur, Θ_{s} ≈ 1. The results are discussed in terms of Gurney model.

Keywords

EN

79.90.+b; 73.30.+y; 79.60.Dp

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 1995
• Volume: 88
• Issue: 6
• Pages: 1151-1160

Dates

published

1995-12

received

1995-05-31

(unknown)

1995-07-18

Contributors

author

R. Błaszczyszyn

• Institute of Experimental Physics, University of Wrocław, Pl. Maxa Borna 9, 50-204 Wrocław, Poland

author

M. Błaszczyszynowa

• Institute of Experimental Physics, University of Wrocław, Pl. Maxa Borna 9, 50-204 Wrocław, Poland

author

W. Gubernator

• Institute of Experimental Physics, University of Wrocław, Pl. Maxa Borna 9, 50-204 Wrocław, Poland