Quick Overview #
Tougaard Background #
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How it works: Models background due to inelastic scattering over a wider energy range using theoretical cross-sections.
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When to use:
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Surfaces with significant inelastic loss structures (e.g., metals, oxides)
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When analyzing valence band or REELS-like features
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Pros: Physically realistic, accurate for quantitative work
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Cons: Slower, complex, depends on material parameters
Basics of Tougaard Application #
Much like with the general background application, we use the peak window button to start applying Tougaard backgrounds.
In the Tougaard tab, we can start applying a Tougaard background to our data.
Tougaard Parameters #
Using the mode ‘Custom B,C’, or ‘Custom B, C, D’ you can modify the Tougaard form:
U, W, and A — empirical constants in the Tougaard formula:
where E is energy, and E0 is the peak energy.
These control the shape of the background tail:
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U: controls broadness (default ~100) (C parameter)
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W: weight of the long tail (B parameter)
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A: amplitude scaling (A parameter)
Preset Tougaard Background Types #
Avantage contains multiple preset groups of parameters that have been derived for a number of materials. Using the mode dropdown, you can select these before inserting a background.
Using the custom modes you can design backgrounds for any material – but you must know how to derive these parameters! See our Tougaard page for more information.
Example: Aluminium with thin oxide layer #
The Tougaard background simulated loss processes – including plasmon peaks. In the example below we show an Al type background applied to an Al foil with a thin oxide overlayer. Since this is not pure Al, our background does not match perfectly, and we must apply a slight Y-offset to get us close to the data. Nevertheless, we can see the simulated plasmon peaks in the background.
