OSA's Digital Library

Optics Express

Optics Express

  • Editor: Michael Duncan
  • Vol. 13, Iss. 6 — Mar. 21, 2005
  • pp: 2141–2152
« Show journal navigation

Investigation of site-selective symmetries of Eu3+ ions in KPb2Cl5 by using optical spectroscopy

Concepción Cascales, Joaquín Fernández, and Rolindes Balda  »View Author Affiliations


Optics Express, Vol. 13, Issue 6, pp. 2141-2152 (2005)
http://dx.doi.org/10.1364/OPEX.13.002141


View Full Text Article

Acrobat PDF (217 KB)





Browse Journals / Lookup Meetings

Browse by Journal and Year


   


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools

Share
Citations

Abstract

Site-selective time-resolved spectroscopy of Eu3+ in KPb2Cl5 has been investigated by using fluorescence line narrowing technique. A crystal field analysis and simulation of the experimental results has been performed in order to parametrize the crystal field at the Eu3+ sites. Three symmetry independent crystal field sites for the rare-earth ion in this crystal were found. A plausible argument about the crystallographic nature of these sites is given.

© 2005 Optical Society of America

1. Introduction

In RE doped KPb2Cl5 crystals the RE ions are supposed to substitute the lead (Pb2+) ions whereas potassium (K+) vacancies are assumed to provide charge compensation [7

7. M.C. Nostrand, R.H. Page, S.A. Payne, L.I. Isaenko, and A.P. Yelisseyev, “Optical properties of Dy3+-and Nd3+-doped KPb2Cl5,” J. Opt. Soc. Am. B 18, 264–276 (2001). [CrossRef]

]. However, it is well established that the presence of structural defects in the vicinity of the RE ions may modify the local crystal-field symmetry and strength and may lead to a variety of nonequivalent RE optical centers. Unfortunately at this moment no accordance exists with respect to either the number of independent positions for Pb atoms or their coordination [7

7. M.C. Nostrand, R.H. Page, S.A. Payne, L.I. Isaenko, and A.P. Yelisseyev, “Optical properties of Dy3+-and Nd3+-doped KPb2Cl5,” J. Opt. Soc. Am. B 18, 264–276 (2001). [CrossRef]

,10

10. N.W. Jenkins, S.R. Bowman, S. O′Connor, S.K. Searles, and J. Ganem, “Spectroscopic characterization of Er-doped KPb2Cl5 laser crystal,” Opt. Mat. 22, 311–320 (2003). [CrossRef]

,14

14. K. Nitsch, M. Dusek, M. Nikl, K. Polák, and M. Rodová, “Ternary alkali lead chlorides: crystal growth, cristal structure, absorption and emission properties,” Prog. Crystal Growth and Charact. 30, 1–22 (1995). [CrossRef]

]. If there are various nonequivalent crystallographic sites for Pb2+ ion in the material lattice one could expect a rather complex spectroscopic behavior for the RE active ions. However, a recent spectroscopic characterization of Er3+ in KPb2Cl5 performed by Jenkins el al. [10

10. N.W. Jenkins, S.R. Bowman, S. O′Connor, S.K. Searles, and J. Ganem, “Spectroscopic characterization of Er-doped KPb2Cl5 laser crystal,” Opt. Mat. 22, 311–320 (2003). [CrossRef]

] concluded that the erbium ion replaced only one of the two available non-equivalent lead ion sites. In order to understand the underlying reasons for this behaviour and to clarify the nature of the RE environments in potassium lead chloride-type crystals we have undertaken the study of the site-resolved luminescence of Eu3+ in KPb2Cl5 account taken of the adequacy of the dopant ion as a structural probe. Since 5D0 state is nondegenerate under any symmetry, the structure of the 5D07FJ emission is only determined by the splitting of the terminal levels caused by the local crystal field. Moreover, as the 7F0 level is also nondegenerate, site-selective excitation within the inhomogeneous broadened 7F05D0 absorption band can be performed by using fluorescence line narrowing (FLN) technique to distinguish among different local environments around the rare-earth ions. On the ground of the experimental results a crystal-field analysis and simulation of the energy level schemes have also been performed in order to parametrize the crystal-field around the Eu3+ ions. As a conclusion, we found evidences about the existence of at least three symmetry independent crystal field sites for the RE ions in this crystal. A plausible argument about the crystallographic nature of these sites is finally given.

2. Experimental techniques

Single crystals of non-hygroscopic ternary potassium-lead chloride KPb2Cl5 doped with Eu3+ ions, typically 2 cm long and 1 cm in diameter, have been grown in our laboratory by the Bridgman technique, in a chlorine atmosphere, with a two-zone transparent furnace, a vertical temperature gradient of 18°C/cm, and a 1mm per hour growth rate. Quartz ampoules with a pointed end were used as seed selectors to promote single crystal growth. The pure crystals are transparent and colourless. The Eu3+ content was 0.5 mol % in the melt. The plates with approximate dimensions of 8×4×2 mm3 were cut from blocks and polished for spectroscopic measurements.

Resonant time-resolved FLN spectra were performed by exciting the sample with a pulsed frequency doubled Nd:YAG pumped tunable dye laser of 9 ns pulsed width and 0.08 cm-1 linewidth and detected by an EGG & PAR Optical Multichannel Analyzer. The measurements were carried out by keeping the sample temperature at 10 K in a closed cycle helium cryostat.

For lifetime measurements, the fluorescence was analyzed with a 0.25 m Jobin-Ybon monochromator and the signal detected by a Hamamatsu R636 photomultiplier. Data were processed by a Tektronix oscilloscope.

3. Experimental results

3.1 FLN spectra

Time-resolved line-narrowed fluorescence spectra of the 5D07F0-6 transitions of Eu3+ doped KPb2Cl5 crystal were obtained at 10 K by using different resonant excitation wavelengths into the 7F05D0 transition, and at different time delays after the laser pulse. Depending on the excitation wavelength the emission spectra present very diverse characteristics, mainly regarding the number of observed 5D07FJ transitions, their relative intensity and the magnitude of the observed crystal-field splitting for each 7FJ state. As an example Fig. 1 shows the spectra corresponding to the 5D07F0,1,2 transitions obtained with a time delay of 10 µs after the pump pulse at four different pumping wavelengths. At the lowest excitation wavelength, 578.5 nm, the 5D07F0 transition shows the presence of at least three resolved peaks which indicates the existence of different RE sites. Indeed, the 5D07F0,1,2 spectra obtained by exciting at 579.5, 580.1, and 581 nm respectively, selectively show the presence of the three isolated Eu3+ sites.

We shall hereafter refer to the optical features of these spectra as originating from sites I (λexc=579.5 nm), II (λexc=580.1 nm) and III (λexc=581 nm). On the other hand, while tuning the excitation pulse at other wavelengths the observed spectra consist of overlapped series of peaks corresponding to the three sites. The presence of the line for the 5D07F0 transition in each spectrum indicates a site of Cnv, Cn or Cs symmetry for Eu3+. These symmetries allow the transition as an electric dipole process, according to the group theory selection rules, with a linear term in the crystal-field expansion [16

16. G. Blasse, A. Bril, and W.C. Nieuwpoort, “On the Eu3+ fluorescence in mixed metal oxides. Part I-The crystal structure sensitivity of the intensity ratio of electric and magnetic dipole emission,” J. Phys. Chem. Solids 27, 1587–1592 (1966). [CrossRef]

18

18. W.C. Nieuwpoort and G. Blasse, “Linear Crystal-Field Terms and 5D0-7F0 transition of Eu3+ ion,” Sol. State Commun. 4, 227–232 (1966). [CrossRef]

]. By making use of the selection rules for induced electric dipole (ED) and magnetic dipole (MD) transitions, that is, from the comparison between the derived number of possible and experimentally observed 5D07F0-6 transitions, it is in principle likely to discriminate between different symmetry point groups for these Eu3+ optical centers [19

19. C. Görller-Walrand and K. Binnemans, “Rationalization of Crystal-Field Parametrization”, in Handbook on the Physics and Chemistry of Rare Earths, K.A. Gschneidner Jr. and L. Eyring, eds. (Elsevier Science, Amsterdam, 1996), vol.23 pp. 121–283. [CrossRef]

].

Fig. 1. 5D0→F0, 1, 2 emissions of Eu3+ in KPb2Cl5

In this way, the spectra obtained with excitation wavelengths 579.5 and 580.1 nm display, in both cases, three Stark levels for the 5D07F1 transition and five levels in the hypersensitive 5D07F2 region, meaning that the degeneracy of these two states is completely lifted, that is, I and II Eu3+ optical centers are located in crystal sites with C2v or lower symmetry. These levels as well as those observed for remaining transitions from 5D0 to the ground 7FJ manifold are included in Table 1 (shown in the Appendix). However, the noticeably different patterns observed when comparing the fluorescence spectra from I and II sites indicate very distinct Eu3+ crystalline environments. As can be observed in Fig. 1, the intensity ratio of the 5D07F1 and 5D07F2 emissions is about one for site I, whereas the relationship is reduced to about one third for site II. Regarding the rest of the 5D07FJ transitions, shown in Fig. 2, it is also surprising to find the very low intensity of the 5D07F3 transition detected at excitation wavelength 580.1 nm. This transition, forbidden in first order by the electric/magnetic dipole selection rules, is observed only as a consequence of the J-mixing, which mixes the 7F3 wavefunctions with other 7FJ ones, through the second-and fourth-order crystal-field (CF) parameters. Finally, the quite large observed splitting of 7F1 for site I, 382 cm-1, clearly contrasts with the corresponding to site II, of about 87 cm-1.

Fig. 2. 5D0→F0→6 emissions of Eu3+ in KPb2Cl5

On the other hand, the spectra obtained by exciting at 581 nm only show two CF levels for the 5D07F1 transition, and three levels (one of them with a very weak intensity) for the 5D07F2 emission. These results suggest that Eu3+ in site III is in the presence of a rather higher hexagonal, trigonal or tetragonal symmetry. A careful analysis of the whole set of levels from 5D07FJ transitions clearly allows to exclude higher hexagonal D6, C6v,C6, D3h, and C3h symmetries, as well as tetragonal D4, for which the number of energy levels to be likely observed would be lesser than in the identified set, whereas tetragonal C4v, D2d, S4 and C4, and trigonal C3v, D3 and C3 symmetries seem to be a better approach and deserve a more detailed evaluation. The results corresponding to attempts of parametrization of CF effects for Eu3+ located in site III developed on the basis of local C4v and C3v or D3 symmetries are presented in Table 2 (shown in the Appendix).

3.2 Lifetimes

As could be expected, if there are different sites for the Eu3+ion, the lifetime of state 5D0 should depend on the excitation wavelengths. We have measured the lifetime of the 5D0 state at three different excitation wavelengths (579.5, 580.1, and 581 nm), which correspond to those at which the three sites are selectively resolved, and collecting the luminescence at the highest intensity Stark component of the 5D07F4 transition. The experimental decays are well described by a single exponential function to a good approximation. The values of the measured lifetime are 1.1 ms, 0.55 ms, and 0.14 ms for sites I, II, and III respectively.

4. Crystal-field analysis and simulation of the energy level schemes

It is well known that Eu3+ is the best choice for a ‘crystal-field probe’ in a given host. Their ground 7F0 as well as the fluorescent 5D0 states are non-degenerate, and have symmetry label Γ1, which largely simplifies the interpretation of the spectra. By making use of the selection rules for induced ED and MD transitions, it is possible to discriminate between different point symmetries for an observed optical center in a given host. Moreover, there is a straightforward relation between the CF splitting of 2S+1LJ levels with small J values, especially for J=1 and 2, and the CF parameters. In this case, CF parameters can be deduced directly from the experiment.

The phenomenological CF simulation of the Eu3+ energy level scheme can be accurately conducted on the strongly reduced basis of the 7FJM set alone, i.e., 49|SLJM J 〉 levels. The use of this truncation is enabled by two characteristics of the 4f6 configuration: firstly, the 7FJ (J=0-6) sextuplet is relatively well isolated from the rest of the configuration (the energy gap between 7F6 and 5D0 is ~12 000 cm-1), which renders the mixing of the wavefunctions negligible, and secondly, the CF operator only mixes levels with the same multiplicity. Evidently, even with the J-mixing included, not all the interactions are taken into account, as non-diagonal spin-orbit interactions that create small components of the 5DJ levels into the 7FJ wavefunctions. Therefore, some “intermediate parameters” have to be introduced, one for each 7FJ state, in order to overlap experimental and calculated barycenters.

The method used for calculating the energy levels of Eu3+ in a crystalline environment usually considers the single-particle CF theory. Following the formalism of Wybourne [20

20. B.G. Wybourne, Spectroscopic Properties of Rare Earths, Wiley, New York, 1965.

], the CF Hamiltonian is expressed as a sum of products of tensor operators (Cqk ) i , with real Bqk and complex Sqk parameters as coefficients, these later appropriated to the Eu3+ site symmetry in the host

HCF=k=24,6q=0k[Bqk(Cqk+(1)qCqk)+iSqk(Cqk(1)qCqk)]

For I and II Eu3+sites in KPb2Cl5, which in accordance with the above fluorescence spectra present C2v or lower symmetries, we have carried out the parametrization by initially considering the nine real Bqk parameters of a C2v CF potential. Secondly, fourth and sixth-rank parameters were carefully determined from the adequate reproduction of 7F1, 7F2 and the remaining observed 7FJ splittings, respectively, before considering all observed energy levels and a free variation of all CF parameters. Thirty energy levels for site I and thirty three ones for site II, included in Table 1, were used to derive these parameters. The phenomenological sets of refined C2v parameters for sites I and II are presented in Table 2. After this first step, the preceding nine CF parameters can be considered as the starting ones for the simulation of the same energy level patterns in the lower Cs/C2 symmetry, which involves the corresponding non-zero complex Sqk parameters. The results are included in Table 2.

A scheme of 18 Stark levels was considered for the simulation of the sequence of Eu3+7FJ energy levels in site III, when the C4v symmetry is evaluated. Two more levels, which were seen from weak transitions, were added for the simulation with the C3v or D3 symmetry, Table 1. Results of refined CF parameters for both fittings C4v and C3v/D3 are included in Table 2. All the performed calculations were conducted with the aid of a matrix diagonalizing program [21

21. P. Porcher, Fortran routine GROMINET for simulation of real and complex crystal-field parameters on 4f6 and 4f8 configurations, (unpublished 1995).

] which took into account the J mixing between wavefunctions with different J and M values. The least squares refinement between the experimental and calculated energy levels was carried out by minimizing the rms function defined as σ=[(Eexp -Ecal )2/(Nlev -Npar )]1/2, where Eexp and Ecal correspond to the experimental and calculated energy level values, and Nlev and Npar the number of levels and parameters, respectively. Figure 3 shows the observed and calculated energy levels for the three sites.

Fig. 3. Observed (o) and calculated (c) energy levels for the three Eu3+ sites

5. Discussion

The existence of diverse Eu3+ optical centers must be explained on the basis of the crystal structure of the KPb2Cl5 host in which they are embedded, that is, three different crystallographic sites for Eu3+ in europium-doped KPb2Cl5 crystal must be assumed.

According to X-ray analysis, biaxial crystals KPb2Cl5 present the monoclinic symmetry of the space-group P21/c, with lattice parameters (Å) α=8.831(2), b=7.886(2) and c=12.430(3), β=90.14 (2)°, V=865.6(4) and Z=4 [14

14. K. Nitsch, M. Dusek, M. Nikl, K. Polák, and M. Rodová, “Ternary alkali lead chlorides: crystal growth, cristal structure, absorption and emission properties,” Prog. Crystal Growth and Charact. 30, 1–22 (1995). [CrossRef]

]. The β value near 90° indicates that the crystal is nearly orthorhombic. Although all studies on the crystal structure of KPb2Cl5 reveal that the [PbCl6]4-distorted octahedron is a principal element, no accordance exists with respect to either the number of independent positions for Pb atoms or their coordination. Thus, while some authors report the existence of four non-equivalent Pb sites, [7

7. M.C. Nostrand, R.H. Page, S.A. Payne, L.I. Isaenko, and A.P. Yelisseyev, “Optical properties of Dy3+-and Nd3+-doped KPb2Cl5,” J. Opt. Soc. Am. B 18, 264–276 (2001). [CrossRef]

,22

22. S.V. Myagkota, A.S. Voloshinovskii, I.V. Stefanskii, M.S. Mikhalik, and I.P. Pashuk, “Reflection and emission properties of lead-based perovskite-like crystals,” Radiation Measurements 29, 273–277 (1998). [CrossRef]

] others point to Pb occupying two symmetrically independent positions [14

14. K. Nitsch, M. Dusek, M. Nikl, K. Polák, and M. Rodová, “Ternary alkali lead chlorides: crystal growth, cristal structure, absorption and emission properties,” Prog. Crystal Growth and Charact. 30, 1–22 (1995). [CrossRef]

]. In this last case, the Pb(1) coordination can be described as a distorted mono-capped octahedron (coordination number CN=7), with the seventh apex at distance >3.1 Å, and Pb(2) is located in the center of a tricapped trigonal prism of chlorine atoms (CN=9), where one of the capping ligands is at the large distance ~4.2 Å, [14

14. K. Nitsch, M. Dusek, M. Nikl, K. Polák, and M. Rodová, “Ternary alkali lead chlorides: crystal growth, cristal structure, absorption and emission properties,” Prog. Crystal Growth and Charact. 30, 1–22 (1995). [CrossRef]

] being thus more reasonable to regard this Pb(2) coordination polyhedron as a bi-capped trigonal prism (CN=8) of chlorine atoms. Anyway, if a smaller coordination sphere around Pb atoms is considered, Pb(1) will be in a purely octahedral environment, CN=6, with Pb-Cl distances <3Å, and Pb(2) possesses an umbrella-like environment with two other more remote Cl-, at around 3.2 Å, and then CN=7 [23

23. L. Isaenko, A. Yelisseyev, A. Tkachuk, S. Ivanova, S. Vatnik, A. Merkulov, S. Payne, R. Page, and M. Nostrand, “New laser crystal based on KPb2Cl5 for IR region,” Mater. Science and Engineering B81188–190 (2001). [CrossRef]

].

The distribution of chlorine atoms around K corresponds to a tricapped trigonal prism TTP (CN=9), where one of the equatorial capping atoms is at distance ~3.8 Å. Figure 4 shows the coordination polyhedra around Pb(1) (CN=7), Pb(2) (CN=9) and K (CN=9) respectively, in KPb2Cl5.

Eu3+ ions are supposed to substitute Pb2+ in the above positions, and the charge compensation will be ensured by K+ vacancies. However taking into account that the K+ coordination polyhedron is similar to the one described for Pb(2), and that actually the planes occupied by Pb2+ and K+ ions alternate within the framework [14

14. K. Nitsch, M. Dusek, M. Nikl, K. Polák, and M. Rodová, “Ternary alkali lead chlorides: crystal growth, cristal structure, absorption and emission properties,” Prog. Crystal Growth and Charact. 30, 1–22 (1995). [CrossRef]

], the possibility of a further Eu3+ access to K+ sites should be also considered though it would suppose a hardly stable local distribution in the crystal host requiring a nearby Pb2+ vacancy for charge compensation.

Fig. 4. Coordination polyhedra of Pb and K in KPb2Cl5. Their site symmetries are Pb(1)=C2/Cs, K=D3/C3v, and Pb(2)~C2v. Grey, red, yellow, and blue balls represent Pb(1), K, Pb(2), and Cl atoms, respectively. Crystal data were derived from Ref. 14.

Simulations of spectra for Eu3+ located in C2v I and II sites yielded energy levels schemes in very good agreement with the experimental data. They were, however, undoubtedly improved when the complex Sqk parameters of the symmetry C2/Cs were introduced, since σ deviations as well as residues decreased significantly. Anyway, complex CF parameters for site II are really weaker, with values of only a few cm-1, and this suggests that the deviation from the higher C2v is, in this case, negligible. By the contrary, results from the fit under C2/Cs symmetry for site I reveal rather important values for complex Sqk parameters, mainly for sixth-rank ones. Consequently, it seems that site I is far more distorted than site II from the initially considered C2v symmetry.

On the other hand, independently of the symmetry considered, the second-order CF parameters for site II are always small, and consequently the J-mixing through the 7F1 wavefunctions will be also small, which explains the above indicated low intensity for the 5D07F3 transition.

Finally, the important difference between absolute values of B02 and B22 parameters for each site reflects the considerably different splitting of their corresponding 7F1 levels.

To further assess the likeliness of current phenomenological parametrizations of crystal field (CF) effects for the three Eu3+ crystal sites resolved in KPb2Cl5, we have also carried out semi-empirical simulations of the CF features observed. They have been conducted through the Simple Overlap Model (SOM) for the crystal field [25

25. P. Porcher, M. Couto dos Santos, and O. Malta, “Relationship between phenomenological crystal field parameters and the crystal structure: The simple overlap model,” Phys. Chem. Chem. Phys. 1, 397–405 (1999). [CrossRef]

]. Benefiting from the fact that the SOM model uses the crystallographic positions of the Eu(Pb1)Cl7, Eu(Pb2)Cl9 and Eu(K)Cl9 coordination polyhedra in the estimation of CF parameters, these calculations have supposed some little modifications (±10 %) in Eu (in Pb(1), Pb(2) and K sites) -Cl distances, with regards to those in Ref. 14. These atom displacements are needed to account for distortions induced in the actual KPb2Cl5 host, which arise from the existence of Pb vacancies necessary for charge compensation. Table 3 (shown in the Appendix) summarizes the main FLN experimental results together with the relationship between the second order calculated crystal field parameters and the ones simulated by using the crystallographic coordinates of the nearest ligands at the proposed lattice sites occupied by the Eu3+ ion.

In summary, if we take into account the proclivity of lanthanide ions for CN=9 within a more or less distorted tricapped trigonal prism [24

24. Cotton and Wilkinson, Advanced Inorganic Chemistry (Wiley1980).

] and that Pb vacancies are rather difficult to achieve in the KPb2Cl5 due to the framework, we can easily understand why Eu3+ in site Pb(2) is the more abundant one, nearly 97% in potassium lead chloride crystal.

6. Conclusion

By using fluorescence line narrowing technique we have demonstrated the existence of three different local environments around the RE ions in KPb2Cl5. On the ground of the experimental results, the crystal-field analysis and simulation of the energy level schemes allow to connect the predicted symmetry of the resolved sites with the crystal structure. In conclusion, the RE ions may occupy both the Pb and K sites but the luminescence results suggest that RE ions occupying the Pb(2) site is most likely to occur.

Appendix

Table 1. Observed and calculated energy levels (cm-1) of observed Eu3+ optical centers in KPb2Cl5

table-icon
View This Table
| View All Tables

Table 2. Phenomenological crystal-field parameters (cm-1) for observed Eu3+ optical centers in KPb2Cl5

table-icon
View This Table
| View All Tables

Table 3. Summary of spectroscopic results and crystal field calculation and simulation

table-icon
View This Table
| View All Tables

Acknowledgments

This work was supported by the Spanish Government MEC (MAT2004-03780 and MAT2004-02001) and Basque Country University (UPV13525/2001).

References and links

1.

G.L. Vossler, C.L. Brooks, and K.A. Winik, “Planar Er:Yb glass ion exchanged waveguide laser,” Electron. Lett. 31, 1162–1163 (1995). [CrossRef]

2.

T.H. Whitley, C.A. Millar, R. Wyatt, M.C. Brierley, and D. Szebesta, “Upconversion pumped green lasing in erbium doped fluorozirconate fibre,” Electron. Lett. 27, 1785–1786 (1991). [CrossRef]

3.

J.E. Roman, P. Camy, M. Hempstead, W.S. Brocklesby, S. Nouth, A. Beguin, C. Lerminiaux, and J. S. Wilkinson, “Ion-exchanged Er/Yb waveguide laser at 1.5 µm pumped by laser diode,” Electron. Lett. 31, 1345–1346 (1995). [CrossRef]

4.

A. Pollack and D.B. Chang, “Ion-pair upconversion pumped laser emission in Er3+ ions in YAG, YLF, SrF2, and CaF2 crystals,” J. Appl. Phys. 64, 2885–2893 (1988). [CrossRef]

5.

M.C. Nostrand, R.H. Page, S.A. Payne, W.F. Krupke, P. G. Schunemann, and L.I. Isaenko, “Spectroscopic data for infrared transitions in CaGa2S4:Dy3+ and KPb2Cl5: Dy3+,” OSA TOPS 19, 524–528 (1998).

6.

M.C. Nostrand, R.H. Page, S.A. Payne, W.F. Krupke, P. G. Schunemann, and L.I. Isaenko, “Room temperature CaGa2S4:Dy3+ laser action at 2.43 and 4.31 µm and KPb2Cl5: Dy3+ laser action at 2.43 µm,” OSA TOPS 26, 441–449 (1999).

7.

M.C. Nostrand, R.H. Page, S.A. Payne, L.I. Isaenko, and A.P. Yelisseyev, “Optical properties of Dy3+-and Nd3+-doped KPb2Cl5,” J. Opt. Soc. Am. B 18, 264–276 (2001). [CrossRef]

8.

R. Balda, M. Voda, M. Al-Saleh, and J. Fernández, “Visible luminescence in KPb2Cl5:Pr3+crystal,” J. Lumin. 97, 190–97 (2002). [CrossRef]

9.

A. Mendioroz, J. Fernández, M. Voda, M. Al-Saleh, R. Balda, and A. J. Garcia-Adeva, “Anti-Stokes laser cooling in Yb3+-doped KPb2Cl5 crystal,” Opt. Lett. 27, 1525–1527 (2002). [CrossRef]

10.

N.W. Jenkins, S.R. Bowman, S. O′Connor, S.K. Searles, and J. Ganem, “Spectroscopic characterization of Er-doped KPb2Cl5 laser crystal,” Opt. Mat. 22, 311–320 (2003). [CrossRef]

11.

R. Balda, J. Fernández, A. Mendioroz, M. Voda, and M. Al-Saleh, “Infrared-to-visible upconversion processes in Pr3+/Yb3+-codoped KPb2Cl5,” Phys. Rev. B 68, 1651011–1651017 (2003). [CrossRef]

12.

R. Balda, A. J. Garcia-Adeva, M. Voda, and J. Fernández, “Upconversion processes in Er3+-doped KPb2Cl5,” Phys. Rev. B 69, 2052031–2052038 (2004). [CrossRef]

13.

M. Voda, M. Al-Saleh, R. Balda, J. Fernández, and G. Lobera “Crystal Growth of Rare-earth-doped Ternary Potassium Lead Chloride Single Crystals by the Bridgman Method,” Opt. Mat. 26, 359–363 (2004). [CrossRef]

14.

K. Nitsch, M. Dusek, M. Nikl, K. Polák, and M. Rodová, “Ternary alkali lead chlorides: crystal growth, cristal structure, absorption and emission properties,” Prog. Crystal Growth and Charact. 30, 1–22 (1995). [CrossRef]

15.

R. Balda, J. Fernández, J.L. Adam, and M.A. Arriandiaga, “Time-resolved fluorescence-line narrowing and energy transfer studies in a Eu3+-doped fluorophosphate glass,” Phys. Rev. B 54, 12076–12086 (1996). [CrossRef]

16.

G. Blasse, A. Bril, and W.C. Nieuwpoort, “On the Eu3+ fluorescence in mixed metal oxides. Part I-The crystal structure sensitivity of the intensity ratio of electric and magnetic dipole emission,” J. Phys. Chem. Solids 27, 1587–1592 (1966). [CrossRef]

17.

G. Blasse and A. Bril, “On the Eu3+ fluorescence in mixed metal oxides. II The 5D0-7F0 emission,” Philips Res. Repts. 21, 368–378 (1966).

18.

W.C. Nieuwpoort and G. Blasse, “Linear Crystal-Field Terms and 5D0-7F0 transition of Eu3+ ion,” Sol. State Commun. 4, 227–232 (1966). [CrossRef]

19.

C. Görller-Walrand and K. Binnemans, “Rationalization of Crystal-Field Parametrization”, in Handbook on the Physics and Chemistry of Rare Earths, K.A. Gschneidner Jr. and L. Eyring, eds. (Elsevier Science, Amsterdam, 1996), vol.23 pp. 121–283. [CrossRef]

20.

B.G. Wybourne, Spectroscopic Properties of Rare Earths, Wiley, New York, 1965.

21.

P. Porcher, Fortran routine GROMINET for simulation of real and complex crystal-field parameters on 4f6 and 4f8 configurations, (unpublished 1995).

22.

S.V. Myagkota, A.S. Voloshinovskii, I.V. Stefanskii, M.S. Mikhalik, and I.P. Pashuk, “Reflection and emission properties of lead-based perovskite-like crystals,” Radiation Measurements 29, 273–277 (1998). [CrossRef]

23.

L. Isaenko, A. Yelisseyev, A. Tkachuk, S. Ivanova, S. Vatnik, A. Merkulov, S. Payne, R. Page, and M. Nostrand, “New laser crystal based on KPb2Cl5 for IR region,” Mater. Science and Engineering B81188–190 (2001). [CrossRef]

24.

Cotton and Wilkinson, Advanced Inorganic Chemistry (Wiley1980).

25.

P. Porcher, M. Couto dos Santos, and O. Malta, “Relationship between phenomenological crystal field parameters and the crystal structure: The simple overlap model,” Phys. Chem. Chem. Phys. 1, 397–405 (1999). [CrossRef]

OCIS Codes
(140.3380) Lasers and laser optics : Laser materials
(300.6320) Spectroscopy : Spectroscopy, high-resolution

ToC Category:
Research Papers

History
Original Manuscript: January 19, 2005
Revised Manuscript: March 11, 2005
Published: March 21, 2005

Citation
Concepción Cascales, Joaquín Fernandez, and Rolindes Balda, "Investigation of site-selective symmetries of Eu3+ ions in KPb2Cl5 by using optical spectroscopy," Opt. Express 13, 2141-2152 (2005)
http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-13-6-2141


Sort:  Journal  |  Reset  

References

  1. G.L. Vossler, C.L. Brooks, and K.A. Winik, �??Planar Er:Yb glass ion exchanged waveguide laser,�?? Electron. Lett. 31, 1162-1163 (1995). [CrossRef]
  2. T.H. Whitley, C.A. Millar, R. Wyatt, M.C. Brierley, and D. Szebesta, �??Upconversion pumped green lasing in erbium doped fluorozirconate fibre,�?? Electron. Lett. 27, 1785-1786 (1991). [CrossRef]
  3. J.E. Roman, P. Camy, M. Hempstead, W.S. Brocklesby, S. Nouth, A. Beguin, C. Lerminiaux, J. S. Wilkinson, �??Ion-exchanged Er/Yb waveguide laser at 1.5 μm pumped by laser diode,�?? Electron. Lett. 31, 1345-1346 (1995). [CrossRef]
  4. A. Pollack and D.B. Chang, �??Ion-pair upconversion pumped laser emission in Er3+ ions in YAG, YLF, SrF2, and CaF2 crystals,�?? J. Appl. Phys. 64, 2885-2893 (1988). [CrossRef]
  5. M.C. Nostrand, R.H. Page, S.A. Payne, W.F. Krupke, P. G. Schunemann, and L.I. Isaenko, �??Spectroscopic data for infrared transitions in CaGa2S4:Dy3+ and KPb2Cl5: Dy3+,�?? OSA TOPS 19, 524-528 (1998).
  6. M.C. Nostrand, R.H. Page, S.A. Payne, W.F. Krupke, P. G. Schunemann, and L.I. Isaenko, �??Room temperature CaGa2S4:Dy3+ laser action at 2.43 and 4.31 μm and KPb2Cl5: Dy3+ laser action at 2.43 μm,�?? OSA TOPS 26, 441-449 (1999).
  7. M.C. Nostrand, R.H. Page, S.A. Payne, L.I. Isaenko, and A.P. Yelisseyev, �??Optical properties of Dy3+-and Nd3+-doped KPb2Cl5,�?? J. Opt. Soc. Am. B 18, 264-276 (2001). [CrossRef]
  8. R. Balda, M. Voda, M. Al-Saleh, and J. Fernández, �??Visible luminescence in KPb2Cl5:Pr3+ crystal,�?? J. Lumin. 97, 190-97 (2002). [CrossRef]
  9. A. Mendioroz, J. Fernández, M. Voda, M. Al-Saleh, R. Balda, and A. J. Garcia-Adeva, �??Anti-Stokes laser cooling in Yb3+-doped KPb2Cl5 crystal,�?? Opt. Lett. 27, 1525-1527 (2002). [CrossRef]
  10. N.W. Jenkins, S.R. Bowman, S.O´Connor, S.K. Searles, J. Ganem, �??Spectroscopic characterization of Er-doped KPb2Cl5 laser crystal,�?? Opt. Mat. 22, 311-320 (2003). [CrossRef]
  11. R. Balda, J. Fernández, A. Mendioroz, M. Voda, and M. Al-Saleh, �??Infrared-to-visible upconversion processes in Pr3+/Yb3+-codoped KPb2Cl5,�?? Phys. Rev. B 68, 1651011-1651017 (2003). [CrossRef]
  12. R. Balda, A. J. Garcia-Adeva, M. Voda, and J. Fernández, "Upconversion processes in Er3+-doped KPb2Cl5,�?? Phys. Rev. B 69, 2052031-2052038 (2004). [CrossRef]
  13. M. Voda, M. Al-Saleh, R. Balda, J. Fernández, G. Lobera �??Crystal Growth of Rare-earth-doped Ternary Potassium Lead Chloride Single Crystals by the Bridgman Method,�?? Opt. Mat. 26, 359-363 (2004). [CrossRef]
  14. K. Nitsch, M. Dusek, M. Nikl, K. Polák, and M. Rodová, �??Ternary alkali lead chlorides: crystal growth, cristal structure, absorption and emission properties,�?? Prog. Crystal Growth and Charact. 30, 1-22 (1995). [CrossRef]
  15. R. Balda, J. Fernández, J.L. Adam, and M.A. Arriandiaga, �??Time-resolved fluorescence-line narrowing and energy transfer studies in a Eu3+-doped fluorophosphate glass,�?? Phys. Rev. B 54, 12076-12086 (1996). [CrossRef]
  16. G. Blasse, A. Bril, and W.C. Nieuwpoort, �??On the Eu3+ fluorescence in mixed metal oxides. Part I- The crystal structure sensitivity of the intensity ratio of electric and magnetic dipole emission,�?? J. Phys. Chem. Solids 27, 1587-1592 (1966). [CrossRef]
  17. G. Blasse and A. Bril, �??On the Eu3+ fluorescence in mixed metal oxides. II The 5D0 �?? 7F0 emission,�?? Philips Res. Repts. 21, 368-378 (1966).
  18. W.C. Nieuwpoort and G. Blasse, �??Linear Crystal-Field Terms and 5D0�??7F0 transition of Eu3+ ion,�?? Sol. State Commun. 4, 227-232 (1966). [CrossRef]
  19. C. Görller-Walrand and K. Binnemans, �??Rationalization of Crystal-Field Parametrization�??, in Handbook on the Physics and Chemistry of Rare Earths, K.A. Gschneidner Jr. and L. Eyring, eds. (Elsevier Science, Amsterdam, 1996), vol.23 pp. 121-283. [CrossRef]
  20. B.G. Wybourne, Spectroscopic Properties of Rare Earths, Wiley, New York, 1965.
  21. P. Porcher, Fortran routine GROMINET for simulation of real and complex crystal-field parameters on 4f6 and 4f8 configurations, (unpublished 1995).
  22. S.V. Myagkota, A.S. Voloshinovskii, I.V. Stefanskii, M.S. Mikhalik, I.P. Pashuk, �??Reflection and emission properties of lead-based perovskite-like crystals,�?? Radiation Measurements 29, 273-277 (1998). [CrossRef]
  23. L. Isaenko, A. Yelisseyev, A. Tkachuk, S. Ivanova, S. Vatnik, A. Merkulov, S. Payne, R. Page, M. Nostrand, �??New laser crystal based on KPb2Cl5 for IR region,�?? Mater. Science and Engineering B81 188-190 (2001). [CrossRef]
  24. Cotton and Wilkinson, Advanced Inorganic Chemistry (Wiley 1980).
  25. P. Porcher, M. Couto dos Santos, and O. Malta, �??Relationship between phenomenological crystal field parameters and the crystal structure: The simple overlap model,�?? Phys. Chem. Chem. Phys. 1, 397-405 (1999). [CrossRef]

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

Figures

Fig. 1. Fig. 2. Fig. 3.
 
Fig. 4.
 

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited