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Joint Research Group - SyncLab

Soft X-ray absorption spectroscopy

With soft X-ray absorption spectroscopy (XAS) the K absorption edges of light elements such as carbon, nitrogen or oxygen and the L edges of transition metals can be probed, elucidating the chemical environment of e.g. molecular thin films. The use of a laser-produced plasma source in combination with a transmission spectrometer using reflection zone plates enables static[1], quick[2] as well as transient[3] measurements with high efficiency and high resolving power. Measurement times vary from sigle shots (500 ps) to minutes for static spectra to days for stable transient investigations.

Instrument data

NEXAFS spectrometer

Source

Lpp source using Yb:YAG thin disk laser and solid state target

Detectors

CCD

Optics

Reflection zone plates

Samples

Thin homogeneous films (~100 nm – 500 nm), large areas (~ 1mm²) preferred

Experimental parameters

 

Energy range

200 eV – 1300 eV

Resolving power

900  - 1400

Pulse duration

500 ps – 30 ns

Repetition rate

100 Hz

Optical pump wavelength

343 nm – 900 nm

Pump probe delay

Up to 43 ns

Minimal time resolution for quick XAS

10 ms

NEXAFS graphs 1 - enlarged view

top: static [1], quick [2] spectra; bottom: transient spectra [3]