Influence of high hydrostatic pressure on Eu2+-luminescence in KMgF3:Eu2+ crystal

Spectroscopic investigations are presented of KMgF3:Eu2+ crystal under high hydrostatic pressure from ambient to 310 kbar. The sample was excited by 30 ps pulses generated by optical parametric generator (OPG) system with wavelength controlled between 210 and 325 nm. The Grüneisen parameters of individual phonons are obtained from the pressure shift of the Eu2+ emission related to the 6P7/2→8S7/2 transition accompanied by phonon sideband. The luminescence decays exponentially for the pressure below 135 kbar with lifetime of 3.30 ms and slightly nonexponential above 135 kbar, while the average decay time is nearly independent of the pressure. The results obtained for KMgF3:Eu2+ are compared with those for LiBaF3:Eu2+ in which the 6P7/2→8S7/2 emission is replaced by the broadband emission of the 4f65d1→4f7 transition at high hydrostatic pressure.