Solid-state screening effect on the post-collision interaction

Photoexcited $N_{4,5}{O}_1{O}_{2,3}$ Auger transitions for ${\mathrm{La}}^{3+}$ in La${\mathrm{F}}_3$, an insulator, are studied with the photon energy tuned through the $\mathrm{La}4d$ to $4f$ resonant excitations. The post-collision interaction between the photoexcited electron and the Auger electron leads to a shift in the Auger kinetic energies. The shift is reduced by 2.3 eV for the same Auger transitions in La${\mathrm{B}}_6$, a metal, due to metallic screening.