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Updated: May 15, 2026
13:27
Exploring the Effects of Atmospheric Forcings on Evaporation: Experimental Integration of the Atmospheric Boundary Layer and Shallow Subsurface
Published on: June 8, 2015
Field evaporation of oxides: a theoretical study
1Department of Physics and Atmospheric Science, Dalhousie University, Halifax, N.S., Canada B3H 3J5.
Ultramicroscopy
|January 16, 2013
Summary
Density functional theory reveals MgO cluster evaporation pathways. Oxygen desorbs via surface migration or internal recombination, while Mg leaves as doubly charged ions.
Area of Science:
- Surface Science
- Materials Science
- Computational Chemistry
Background:
- Atom probe tomography is crucial for analyzing oxide field evaporation.
- Understanding ion desorption mechanisms is key to interpreting experimental data.
Purpose of the Study:
- Investigate structural changes during MgO field evaporation using DFT.
- Determine potential energy curves, partial charges, and desorption pathways.
- Elucidate the fate of electrons and oxygen during oxide evaporation.
Main Methods:
- Density Functional Theory (DFT) calculations.
- Simulations on MgO clusters.
- Analysis of potential energy surfaces and charge distributions.
Main Results:
- Magnesium (Mg) predominantly evaporates as doubly charged ions (Mg²⁺).
- Observed ions include MgO⁺, MgO₂⁺, MgO²⁺, and O⁺.
- Two primary oxygen desorption channels identified: surface migration and internal recombination.
Conclusions:
- Electrons likely complete the electrical circuit when oxides are on metal tips.
- Oxygen can desorb as atoms/molecules after surface migration or as neutral molecules from internal recombination.
- The study provides insights into the complex field evaporation mechanisms of oxides.
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