title: Communication: On the difficulty of reproducibly measuring PbCl2 X-ray absorption spectra.
abstract: Previous measurements of the X-ray absorption spectra of PbCl2 at the chlorine K-edge have shown significant variation between different studies. Herein, using first principles simulations of X-ray absorption spectroscopy, we show that the observed spectral variations are due to the generation of Cl2 gas and depletion of chlorine from PbCl2, consistent with what is observed during ultraviolet absorption for the same compound. We note that Cl2 gas generation can also be initiated using higher resonant X-ray energies, including Pb X-ray absorption edges. While this casts doubt on previous interpretations of certain measurements, it does indicate a means of generating chlorine gas during in situ experiments by passing high energy x-rays through a hard x-ray transparent medium and onto PbCl2.
authors.affiliation: Stanford Synchrotron Radiation Laboratory, SLAC National Accelerator Lab, Menlo Park, California 94025, USA.
authors.forename: Craig P
authors.initials: CP
authors.lastname: Schwartz
authors.affiliation: Molecular Foundry, Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: David
authors.initials: D
authors.lastname: Prendergast