title: Luminescence of Gd2(WO4)3:Ln3+ at ambient and high hydrostatic pressure.
abstract: This paper presents a spectroscopic characterization of Gd(2)(WO(4))(3):Ln(3+) (Ln=Eu, Pr, Tb and Dy). The luminescence and luminescence kinetics were measured under pressures up to 250 kbar. It was found that pressure quenches the luminescence of Pr(3+) and Tb(3+), whereas the emission of Eu(3+) and Dy(3+) was stable up to 250 kbar. This effect was related to a decrease in the ionization energy of Pr(3+) and Tb(3+) caused by pressure induced increase in energies of the Ln(2+) and Ln(3+) ions with respect to the band edges. Analysis of emission and excitation spectra allowed us to estimate the energies of the ground states of Ln(3+) and Ln(2+) with respect to the valence and conduction band edges of the Gd(2)(WO(4))(3) host. Differences between energies of the ground states of Ln(2+) and Ln(3+) have also been calculated.
authors.affiliation: Institute of Experimental Physics, University of Gdańsk, Gdańsk, Poland.
authors.forename: S
authors.initials: S
authors.lastname: Mahlik
authors.forename: A
authors.initials: A
authors.lastname: Lazarowska
authors.forename: B
authors.initials: B
authors.lastname: Grobelna
authors.forename: M
authors.initials: M
authors.lastname: Grinberg