Spectroscopic properties and luminescence concentration quenching of the Pr3+ ion in La1−xPrxOCl

doi:10.1016/0022-4596(87)90307-0

Journal of Solid State Chemistry

Volume 68, Issue 2, June 1987, Pages 227-233

https://doi.org/10.1016/0022-4596(87)90307-0 Get rights and content

Abstract

Luminescence spectra ofLa_1−xPr_xOCl(0.01 ≤ x ≤ 0.3) were recorded at liquid helium and room temperature. From these spectra, the energy level diagram of Pr³⁺ in LaOCl was deduced. The decay times of the Pr³⁺ emission in La_1−xPr_xOCl were measured using a high-resolution dye laser system. The linear concentration quenching and exponential decay times are explained assuming cross relaxation and energy transfer between the Pr³⁺ ions.

Reference (25)

BerdowskiP.A.M. et al.
J. Lumin.
(1985)
MalinowskiM. et al.
J. Lumin.
(1986)
MazurakZ.G. et al.
J. Phys. Chem. Solids
(1984)
ChrysochoosJ. et al.
J. Lumin.
(1983)
SzymanskiM.
J. Lumin.
(1983)
DornaufH. et al.
J. Lumin.
(1979)
LempickiA. et al.
J. Lumin.
(1979)
SzymanskiM.
J. Lumin.
(1984)
SzymanskiM.
J. Lumin.
(1984)
DornaufH. et al.
J. Lumin.
(1980)

BerdowskiP.A.M. et al.

Phys. Status Solidi B

(1984)

HegartyJ. et al.

Phys. Rev. B

(1981)

Cited by (26)

A novel high-sensitive optical thermometer based on the multi-color emission in Pr3+ doped LiLaMgWO<inf>6</inf> phosphors
2021, Journal of Luminescence
Citation Excerpt :
Theoretically, the smaller the energy mismatch of the relevant energy levels, the more active the CR process. Based on the previous references, there are two candidate CR channels for the electrons in the 3P0 multiplet: 3P0+3H4→1D2+3H6 (CR-1, ΔE = 500–1000 cm−1 [41,42]) and 3P0+3H4→1G4+1G4 (CR-2, ΔE = ~265 cm−1 [42]), while the major CR channel for the 1D2 emission is attributed to 1D2+3H4→1G4+3F4 (CR-3, ΔE = ~12 cm−1 [43]). These data suggest that the 1D2-involved CR-3 process is more efficient than 3P0-involved CR-1 and CR-2 ones due to its tiny energy mismatch.
Nowadays, optical thermometric materials with high sensing sensitivity in a wide temperature interval are urgently required due to the appealing prospect in the field of sensing technology. Herein, the double perovskite Pr³⁺: LiLaMgWO₆ phosphors are successfully prepared via a high-temperature solid-state reaction method, and their concentration/temperature-dependent luminescence properties are discussed systematically. Upon UV excitation, the samples emit blue (³P₀→³H₄), green (³P₀,₁ → ³H₅) and red emissions (¹D₂→³H₄, ³P₀→³F₂) from Pr³⁺ ions. The different changing tendencies in relation to temperature are observed for the emissions from ³P₀ and ¹D₂ multiplets, which are attributed to the effects of cross-over process to Pr³⁺-W⁶⁺ intervalence charge transfer (IVCT) state, cross relaxation process and multiphonon relaxation process. When the fluorescence intensity ratio (FIR) between ³P₀→³F₂ (654 nm) and ¹D₂→³H₄ (616 nm) transitions is applied for temperature sensing, 0.5%Pr³⁺: LiLaMgWO₆ displays a maximum absolute sensing sensitivity of 2421 × 10⁻⁴ K⁻¹ at 573 K. Moreover, it can keep a comparatively high relative sensitivity (1%~3.25% K⁻¹) and low temperature uncertainty (0.15–0.5 K) over a wide temperature range (~280 K), which are superior to those of many luminescence materials reported previously. The present study may provide useful design information to develop high-sensitive luminescent thermometers with a wide applicable temperature range.
Synthesis and spectral-luminescent properties of La<inf>1-x</inf>Pr<inf>x</inf>Ga<inf>0.5</inf>Sb<inf>1.5</inf>O<inf>6</inf> solid solutions
2019, Ceramics International
Citation Excerpt :
= 457 nm and power density J = 4.65 kW/cm2. The luminescence spectra of the La1-xPrxGa0.5Sb1.5O6 (x = 0.003–0.15), Fig. 7, contain the lines associated with the Pr3+ ions transitions from the 3P0 excited state to the 3H6, 3F2, 3F3, 3F4, [7]. Besides, for samples with a Pr3+ ions concentration x = 0.003–0.07 an additional luminescence band is observed, due to the 1D2→3H4 transition.
The series of La_1-xPr_xGa_0.5Sb_1.5O₆ solid solutions (x = 0–1) with PbSb₂O₆ structure was synthesized. The comparative study of the La_1-xPr_xGa_0.5Sb_1.5O₆ morphology showed all compounds have net microstructures. Herein the Pr concentration increasing leads to particles size decreasing from 400 up to 200 nm in the samples with low Pr content and to recrystallization and coarsening of the particles in Pr-rich ones. Using LaGa_0.5Sb_1.5O₆ as an example, it was shown that the compounds have a wide transmission region in the visible and IR spectral ranges and are characterized by a low-energy phonon spectrum. An analysis of the spectral-luminescent characteristics revealed the presence of a cross-relaxation process (¹D₂→¹G₄) → (³H₄→³F₄) of Pr³⁺ ions for La_1-xPr_xGa_0.5Sb_1.5O₆ at x ≥ 0.07. It was showed that a broadband radiation of thermal nature is observed under laser excitation with λ = 457 nm and a power density of J = 4.65 kW/cm² for the samples with high (x = 0.4–1) praseodymium content.
Dependence of cross-relaxation on temperature and concentration from the 1D <inf>2</inf> level of Pr 3+ in YPO <inf>4</inf>
2012, Journal of Luminescence
Citation Excerpt :
This process, as shown in Fig. 1, is described by the equation Pr(1D2)+Pr(3H4)→Pr(1G4)+Pr(3F3,4). This process has been observed in other Pr-doped systems, and is a source of quenching of emission from the 1D2 level [10–12]. Of general interest to applications is the radiative efficiency of the emitting level.
We report on the role of cross-relaxation in the decay of the ¹D₂ level of trivalent Pr in YPO₄ in crystals with Pr concentrations of 0.1%, 1%, 2%, and 5%. We have found that the ¹D₂ level decay is purely radiative in the low-doped system. As the Pr concentration is increased, the ¹D₂ luminescence is quenched due to a cross-relaxation energy transfer between two Pr ions. The temporal behavior of the ¹D₂ luminescence following pulsed excitation has been monitored in each sample at temperatures between 30 K and 300 K, and all decay curves were fit to the Yokota–Tanimoto model. The decay times decrease as temperature increases, due to an increase in both the radiative rate and the energy transfer rate with temperature. There is little evidence of diffusion at any temperature, even in the more concentrated samples. We have also fit the decay curves using the LumiTrans computer simulation. A comparison of the fits to the decay curves of the two methods is presented.
Optical characterizations of Er3+-doped KLa(PO<inf>3</inf>)<inf>4</inf> phosphate crystals
2010, Optical Materials
Absorption spectra were recorded for the three samples of KLa₁₋_xEr_x(PO₃)₄ crystal, where x = 0.025, 0.05 and 1, at room temperature in the 400–900 nm spectral range. Fluorescent emissions from the ⁴S_3/2 and ⁴F_9/2 multiplets were observed under pulsed laser excitation in the ²H_11/2 multiplet $(λ_{exc} = 532 nm)$ and in the ⁴G_9/2 multiplet (355 nm). The time-resolved luminescence of these emissions has also been studied. The decays are shown to be exponential, with decay times on the order of 1 μs, independently of the erbium content. No significant lengthening of the decay time is observed as erbium concentration decreases from 100 to 2.5 at.%. Non-radiative relaxations related to multiphonon emission have been evoked to be at the origin of the excited state depopulation in the Er³⁺-doped KLa(PO₃)₄ crystals studied. The emission spectra of the lasing transition ⁴I_13/2 → ⁴I_15/2 in Er³⁺-doped KLa(PO₃)₄ phosphate crystals have also been analyzed. The influence of the erbium concentration on this electronic transition has been discussed as well. It was observed that the increase of Er³⁺ ion concentration, in the 2.5–100 at.% range, results in a spectral broadening of the 1.54 μm emission band. Reabsorption has been evoked as the main mechanism to explain the broadening of the ⁴I_13/2 → ⁴I_15/2 emission line.
Luminescence properties of Pr3+ and Ce3+ in KCaF<inf>3</inf> single crystals
1999, Journal of Luminescence
The optical excitation and luminescence spectra of (Pr³⁺,Ce³⁺) ions in KCaF₃ are presented. High-resolution excitation and emission spectra of Pr³⁺ and Ce³⁺ were measured at temperatures between 77 and 293 K. First measurements of KCaF₃ : Ce³⁺ crystal show that there are nonequivalent Ce³⁺ centers which radiate either in UV or visible range. The major Ce³⁺ nonequivalent center in KCaF₃ is Ce³⁺ ion in the site with tetragonal site symmetry (S₄). Energy levels for the 4f² ground configuration of Pr³⁺ in KCaF₃ were established from excitation and fluorescence spectra. Energy levels assignments were made assuming electric-dipole transition selection rules for S₄ site symmetry. Twenty-seven energy levels in the lowest six multiplets of the ground configuration were established. In the analysis of experimental data, the O_h magnetic-dipole selection rules were also considered to explain missing or weak transitions which are allowed in S₄. Spectra of Pr³⁺ in KCaF₃ have been analyzed with a crystal-field Hamiltonians of S₄ or O_h symmetries including J mixing effects. Crystal-field parameters in these Hamiltonians have been determined by the minimization the RMS deviation between calculated and experimental energy Stark levels. We conclude that both model calculations in the S₄ and O_h site symmetries for Pr³⁺ in KCaF₃, provide the basis for a consistently good correlation with data.
The vibronic spectroscopy and luminescence concentration quenching of the Pr3+ ion in La<inf>2</inf>O<inf>3</inf>, LaOF and LiYF<inf>4</inf>
1995, Journal of Physics and Chemistry of Solids
The luminescence spectra of the Pr³⁺ ion in (La_1−xPr_x)₂O₃ (x ⩽ 0.2), La_1−xPr_xOF and LiY_1−xPr_xF₄ (x ⩽ 0.1) powder samples and in LiY_1−xPr_xF₄ (x ⩽ 0.02) single crystals have been investigated. The concentration quenching of the Pr³⁺ emission is observed to be stronger in (La_1−xPr_x)₂O₃. This is ascribed to a more efficient cross-relaxation via superexchange interaction between Pr³⁺ ions. This interaction is shown to be effective over longer distances in La₂O₃:Pr than in LiYF₄:Pr (viz. 10 and 5 Å, respectively). The shift of the 4f5d configuration to lower energies with increasing Pr³⁺ concentration, which is only observed for (La_1−xPr_x)₂O₃, gives support for this conclusion. Moreover, the vibronic spectra and the vibronic transition probabilities of Pr³⁺ in LaOF and La₂O₃ are reported and compared.

View all citing articles on Scopus

^*: On leave from the Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 937, 50-950 Wroclaw, Poland.

View full text

Article preview

Journal of Solid State Chemistry

Abstract

Reference (25)

J. Lumin.

J. Lumin.

J. Phys. Chem. Solids

J. Lumin.

J. Lumin.

J. Lumin.

J. Lumin.

J. Lumin.

J. Lumin.

J. Lumin.

Phys. Status Solidi B

Phys. Rev. B

Cited by (26)

A novel high-sensitive optical thermometer based on the multi-color emission in Pr<sup>3+</sup> doped LiLaMgWO<inf>6</inf> phosphors

Synthesis and spectral-luminescent properties of La<inf>1-x</inf>Pr<inf>x</inf>Ga<inf>0.5</inf>Sb<inf>1.5</inf>O<inf>6</inf> solid solutions

Dependence of cross-relaxation on temperature and concentration from the <sup>1</sup>D <inf>2</inf> level of Pr <sup>3+</sup> in YPO <inf>4</inf>

Optical characterizations of Er<sup>3+</sup>-doped KLa(PO<inf>3</inf>)<inf>4</inf> phosphate crystals

Luminescence properties of Pr<sup>3+</sup> and Ce<sup>3+</sup> in KCaF<inf>3</inf> single crystals

The vibronic spectroscopy and luminescence concentration quenching of the Pr<sup>3+</sup> ion in La<inf>2</inf>O<inf>3</inf>, LaOF and LiYF<inf>4</inf>