Photoinduced formation of N-2 molecules in ammonium compounds

• Via fluorescence yield (FY) and resonant inelastic scattering spectroscopy in the soft X-ray range we find that soft X-rays induce formation of N-2 molecules in solid NH4Cl and in related compounds. The nitrogen molecules form weak bonds in NH4Cl, so that a substantial fraction of the molecules remains in the sample. From measurements of the FY as a function of exposure and temperature, the rates for the photochemical processes are estimated. At elevated temperatures (363 K), several nitrogen atoms are removed from the sample per incoming photon. At lower temperatures (233 K), the rate is reduced to around 0.02 nitrogen atoms for each incoming photon. Virtually all these atoms form N-2 molecules which are bound in the sample. The generality and implications of these results are briefly discussed.

Keyword

x-ray-emission

synchrotron-radiation

nitrogen

chloride

autoionization

spectroscopy

crystals

spectra

NATURAL SCIENCES

TECHNOLOGY

Publication and Content Type

ref (subject category)

art (subject category)