Temperature and Radiation Effects at the Fluorine K-edge in LiF

Published

May 30, 2017

Author(s)

Craig P. Schwartz, Francisco Ponce, Stephan Friedrich, Stephen P. Cramer, John Vinson, David Prendergast

Abstract

The F K-edge of LiF is studied both experimentally and theoretically as a function of temperature. Instantaneous thermal fluctuations in atomic positions are shown in molecular dynamics simulations to increase in amplitude from 0.029 - 0.064 Å in the temperature range from 40 - 298 K. This is sufficient to cause instantaneous deviations from local octahedral atomic symmetry in this rock-salt crystal, resulting in altered electronic structure and symmetry of the lowest core-excited states of F atoms, evident in X-ray absorption at the F K- edge. In addition, with sufficient radiation exposure, a new X-ray absorption peak is seen in experiment, well below the absorption edge of LiF, which, based on calculations and comparison to previous experiments, is assigned to molecular fluorine (F2).

Citation

Journal of Electron Spectroscopy and Related Phenomena

Volume

218

Pub Type

Journals

Download Paper

DOI Link

Keywords

NEXAFS, OCEAN

Citation

Schwartz, C. , Ponce, F. , Friedrich, S. , Cramer, S. , Vinson, J. and Prendergast, D. (2017), Temperature and Radiation Effects at the Fluorine K-edge in LiF, Journal of Electron Spectroscopy and Related Phenomena, [online], https://doi.org/10.1016/j.elspec.2017.05.007 (Accessed April 26, 2024)