X-ray spectroscopic and first principles investigation of lead tungstate under pressure
Eric L. Shirley, Eric J. Cockayne, Joseph Woicik, James M. Ablett
High-energy-resolution fluorescence-detected (HERFD) near-edge x-ray absorption fine structure measurements performed at the Pb and W L3 absorption edges has been used to study the pressure dependence of the local atomic structure of PbWO4 from 0 GPa to 22 GPa. Comparison of measured spectra with density-functional theory (DFT) structural calculations and simulations based on solution of the Bethe-Salpeter equation establish an unambiguous PbWO4-I to PbWO4-III phase transition around 7 GPa. No evidence of either the Raspite or Fergusonite or structures is found. The reduction of core hole-lifetime broadening by HERFD affords this unique experimental determination of crystal field splitting and its sensitivity to the oxygen cage geometry surrounding the Pb and W atoms, affording this definitive identification of the high-pressure phase for PbWO4.
, Cockayne, E.
, Woicik, J.
and Ablett, J.
X-ray spectroscopic and first principles investigation of lead tungstate under pressure, Physical Review B, [online], https://doi.org/10.1103/PhysRevB.104.054119, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=931411
(Accessed November 29, 2023)