title: Pressure evolution of LiBaF(3):Eu(2+) luminescence.
abstract: We investigated the single crystals of LiBaF(3) doped with Eu(2+) using high pressure spectroscopy, where high pressure was applied in a diamond anvil cell. Photoluminescence, time-resolved luminescence and luminescence kinetics at pressures from ambient to 200 kbar and at temperatures from 10 K to ambient were studied. At ambient conditions the luminescence spectra consisted of sharp lines peaked at 360 nm attributed to the [Formula: see text] transitions in the 4f(7) electronic configuration of Eu(2+) (the zero-phonon line and five single-phonon repetitions) and a broad band extending between 375 and 475 nm attributed to Eu(2+) trapped exciton recombination. When pressure was increased the Eu(2+) trapped exciton emission disappears and was replaced by the sharper band peaked at 355 nm, attributed to the [Formula: see text] transition in Eu(2+). To analyze the pressure dependence of luminescence spectra a model of impurity trapped excitons was developed. At temperatures lower than 50 K only the sharp lines related to [Formula: see text] transitions were observed for all pressures considered. Analysis of low temperature spectra allowed us to estimate the energies of the fifth phonon modes and the values of the Grüneisen parameters.
authors.affiliation: Institute of Experimental Physics, University of Gdansk, Wita Stwosza 57, 80-952 Gdansk, Poland.
authors.forename: S
authors.initials: S
authors.lastname: Mahlik
authors.forename: M
authors.initials: M
authors.lastname: Grinberg
authors.forename: Liang
authors.initials: L
authors.lastname: Shi
authors.forename: Hyo Jin
authors.initials: HJ
authors.lastname: Seo