Calibration method at the N K-edge using interstitial nitrogen gas in solid-state nitrogen-containing inorganic...

Area of Science:

• Materials Science
• Atomic and Molecular Physics
• Spectroscopy

Background:

• Soft X-ray beamline calibration is crucial for accurate spectroscopic measurements.
• The Nitrogen K-edge (N K-edge) is a common calibration point.
• Current methods rely on gas-phase molecular nitrogen (N(2)).

Purpose of the Study:

• To investigate the use of solid-state N(2) sources for N K-edge soft X-ray beamline calibration.
• To establish an alternative calibration method that avoids gas-phase measurements.
• To identify suitable solid-state compounds for this application.

Main Methods:

• Utilized ammonium and amine-containing salts as solid-state sources of N(2).
• Investigated beam-induced decomposition of these salts to produce N(2) gas.
• Analyzed calibration spectra using the nu = 0 peak transition of N(2).
• Examined non-nitrogen-containing compounds (e.g., KH(2)PO(4)) and He-purged samples as controls.

Main Results:

• Interstitial N(2) gas can be effectively generated from solid-state ammonium and amine salts.
• Beam-induced decomposition is identified as the primary mechanism for N(2) production.
• Non-nitrogen-containing compounds and nitrate/nitrite salts are unsuitable for calibration due to interfering signals.

Conclusions:

• Solid-state N(2) sources, particularly from ammonium salts, offer a viable alternative for soft X-ray beamline calibration at the N K-edge.
• This method simplifies calibration by eliminating the need for gas-phase N(2) handling.
• Careful selection of precursor materials is essential to avoid spectral interference.