Lidia Żur

Optical transitions of Eu 3+ and Dy 3+ ions in lead phosphate glasses

Lead phosphate glasses containing Eu(3+) and Dy(3+) have been studied. Local structure was verified using Fourier transform (FT)-IR spectroscopy. Emission bands of Eu(3+) and Dy(3+) ions in lead phosphate glasses are observed in the visible spectral range, which correspond to 5D0→7F(J) (J=0,1,2,4) and 4F(9/2)→6H(J/2) (J=15,13,11) transitions, respectively. Shorter luminescence decays from excited states of Eu(3+) and Dy(3+0 are due to the presence of PbO in phosphate glass.

Visible luminescence of dysprosium ions in oxyhalide lead borate glasses

Visible luminescence of Dy(3+) ions in oxyhalide lead borate glasses was examined. Luminescence spectra show two intense bands at 480 nm and 573 nm due to (4)F(9/2)→(6)H(15/2) (blue) and (4)F(9/2)→(6)H(13/2) (yellow) transitions of Dy(3+). Luminescence decays from (4)F(9/2) state and yellow-to-blue luminescence intensity ratios (Y/B) were analysed with PbX(2) (X=F, Cl) content. An introduction of PbX(2) to the borate glass results in the increasing of (4)F(9/2) lifetime and the decreasing of yellow-to-blue luminescence intensity ratio, which is due to reduction of covalency between Dy(3+) and O(2-)/X(-) ions.

Ultraviolet-to-visible downconversion luminescence in solgel oxyfluoride glass ceramics containing Eu 3+ :GdF 3 nanocrystals

GdF3 nanocrystals doped with Eu3+ ions in oxyfluoride glass ceramics were prepared by a solgel method. The structural properties were examined by x-ray diffraction measurements. The effects of gadolinium codoping on europium emission in the prepared solgel glasses and glass ceramics have been studied. The emission bands originating from the 5D0 state of Eu3+ ions are enhanced under excitation of Gd3+ ions by 273 nm line. The electric dipole 5D0→7F2 transitions were dominant in the samples before heat treatment, whereas magnetic dipole 5D0→7F1 transitions had a higher probability in the samples after annealing. The luminescence lifetime for the 5D0 level of Eu3+ ions in the samples after excitation at 273 nm is long lived in comparison to excitation at 393 nm and increased to 190%. Energy transfer from Gd3+ to Eu3+ was observed.

Excitation and luminescence of Dy3+ ions in PbO-P2O5-Ga2O3 glass system

Abstract Lead phosphate glasses singly doped with Dy 3+ ions were studied. The samples were prepared in a glove box in order to eliminate hydroxyl groups. Local structures were examined using FT-IR. Excitation and luminescence spectra for Dy 3+ ions in investigated lead phosphate glasses were registered. Luminescence intensity ratio Y/B related to 4 F 9/2 → 6 H J /2 (where J =15, 13) transitions was determined and luminescence lifetime (τ m ) for the 4 F 9/2 state of Dy 3+ ions were also measured.

Terbium-terbium interactions in lead phosphate glasses

Blue and green luminescence spectra of Tb3+ ions in lead phosphate glasses were examined under UV excitation. The green-to-blue luminescence intensity ratio G/B is considerably reduced with decreasing Tb3+ concentration. Thus, blue emission lines are enhanced in comparison to the main 5D4-7F5 green transition of Tb3+. These effects strongly depend on terbium-terbium interactions in lead phosphate glasses. It was confirmed by luminescence decay curve analysis and calculations using the Inokuti-Hirayama model.

Emission of Eu3+ in sol-gel oxyfluoride glass materials obtained by different preparation methods

Abstract Silica glasses doped with Eu 3+ ions prepared by sol-gel methods were investigated. The X-ray diffraction (XRD) was used to verify the nature of the studied systems. Excitation and emission spectra of Eu 3+ ions in sol-gel glass materials were detected. Red-to-orange luminescence intensity ratios R/O related to integrated intensities of 5 D 0 → 7 F 2 to 5 D 0 → 7 F 1 transitions and luminescence lifetimes for 5 D 0 state of Eu 3+ ions were determined. The results indicated that spectroscopic parameters for Eu 3+ ions strongly depended on reagents and their relative ratios used for sol-gel glass preparation.

Spectroscopic properties of Eu3+, Dy3+ and Tb3+ ions in lead silicate glasses obtained by the conventional high-temperature melt-quenching technique

The luminescence properties of selected rare-earth ions in lead silicate glasses have been studied. Europium, dysprosium and terbium ions were chosen as active dopants. Based on excitation and emission measurements as well as luminescence decay analysis, some spectroscopic parameters for these lanthanide ions were determined. In particular, the intensity ratios R/O (Eu3+), Y/B (Dy3+) and G/B (Tb3+) were calculated. Luminescence lifetimes for the 5D0 state of Eu3+ ions, the 4F9/2 state of Dy3+ ions and the 5D4 state of Tb3+ ions were also determined.

Terbium-doped heavy metal glasses for green luminescence

Compositional-dependent heavy metal lead borate glasses doped with Tb3+ ions were investigated. Green luminescence related to main 5D4→7F5 (543 nm) transition was registered under excitation of 5D3 state of Tb3+ ions. Based on excitation and luminescence measurements, several spectroscopic parameters for Tb3+ ions were examined as a function of heavy metal PbO content. Luminescence decay analysis indicated that the 5D4 luminescence lifetime of Tb3+ reduced from 2.83 to 1.42 ms, when PbO:B2O3 ratio was changed from 1:1 to 4:1.

Transparent glass-ceramics containing Eu3+ and Dy3+ ions for visible optoelectronics

Selected oxyfluoride glasses containing Eu3+ and Dy3+ were heat treated in order to obtain transparent glass-ceramics. Visible emission spectra corresponding to 5D0 - 7FJ (J = 0, 1, 2, 3, 4) transitions of Eu3+ and 4F9/2 - 6HJ/2 (J = 11, 13, 15) transitions of Dy3+ in glass samples before and after heat treatment were registered. The luminescence intensity ratios R (Eu3+) and Y/B (Dy3+) have been analyzed in details. Their values are reduced due to part incorporation of rare earth ions into cubic β-PbF2 crystalline phase.

Influence of M2O3 (M = Al, Ga) glass modifiers on structure, thermal and spectroscopic properties of rare earth ions in lead phosphate based systems

Influence of M2O3 (M = Al, Ga) modifiers oxide on local structure and spectroscopic properties of lead phosphate glasses containing rare earth ions was studied. Among the rare earths, the trivalent europium and erbium ions were selected as an optically active dopants. The thermal properties were examined using DSC, whereas the X-ray diffraction analysis was used in order to verify the structure glass matrix. Luminescence of rare earth ions in lead phosphate glasses was registered in visible and NIR spectral region. The excitation and emission spectra of lead-based systems are presented and discussed in relation to the effect of modifiers oxide M2O3 (M = Al, Ga). Luminescence lifetimes (τm) for the 5D0 state of Eu3+ ions and 4I13/2 state of Er3+ ions were also evaluated.