Pressure and temperature dependence of chromium photoluminescence spectra in fluoride elpasolites

Dolan, J.F.; Rinzler, Andrew G.; Kappers, L.A.; Bartram, R.H.

doi:10.1016/0022-3697(92)90117-v

Cited by 61 publications

(76 citation statements)

References 12 publications

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“…Due to this fact, it can reasonably be explained that E 0 S can be understood through the coupling with the two a 1g and e g stretching modes. For octahedral CrX 3− 6 units (X = F, Cl and Br) in cubic elpasolites no experimental evidence of any coupling of the first excited state, 4 T 2g , with the t 2g shear mode has been reported [24,28,44,45].…”

Section: Coupling Constants For Thementioning

confidence: 99%

“…As the experimental E S values for Mn 2+ -doped cubic fluoroperovskites lie in the 1200-1600 cm −1 region [10] andhω u ≈ 250 cm −1 , the odd phonon contribution to (9) is certainly small when compared to E 0 S . When a hydrostatic pressure is applied on a given system the variations of V a and V e coupling constants and ω a and ω e frequencies around the distance corresponding to equilibrium at P = 0 atm are described by [13,24,26] …”

Section: Coupling Of 4 T 1g Excited State With Local Modes: Stokes Shiftmentioning

confidence: 99%

“…For a T 1g excited state a linear Jahn-Teller coupling with e g and t 2g modes is symmetry allowed together with the coupling to the full symmetric a 1g mode [13,21,24]. The Stokes shift thus depends on the ω e , ω t and ω a frequencies of e g , t 2g and a 1g modes, respectively, in the ground state and also on the corresponding constants (termed V e , V t and V a , respectively) describing the coupling with the first excited state 4 T 1g .…”

Section: Introductionmentioning

confidence: 99%

“…In the case of doped insulating materials the Stokes shift arises basically from the linear coupling of the electronic excited state responsible for the emission with local vibrational modes [21][22][23][24][25][26][27][28]. Due to the localized character of active electrons in both ground and excited states such modes involve basically the distortion of ligands.…”

Section: Introductionmentioning

confidence: 99%

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Optical and vibrational properties of MnF₆⁴⁻complexes in cubic fluoroperovskites: insight through embedding calculations using Kohn–Sham equations with constrained electron density

Garcı́a-Lastra

Wesołowski

Barriuso

et al. 2006

J. Phys.: Condens. Matter

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The local structure and optical and vibrational properties associated with Mn 2+ -doped cubic AMF 3 (A = K, Rb; M = Mg, Zn, Cd) fluoroperovskites are studied by means of embedding calculations using Kohn-Sham equations with constrained electron density. It is shown that while an electronic parameter like 10Dq essentially depends on the Mn 2+ -F − distance, the local vibration frequencies ω i (i = a 1g , e g modes) are dominated by the interaction between F − ligands and nearest M 2+ ions lying along bonding directions. The high ω a values observed for KMgF 3 :Mn 2+ and KZnF 3 :Mn 2+ , the huge variations of ω e and ω a frequencies when the host lattice is changed, as well as the increase of Huang-Rhys factors and the Stokes shift following the host lattice parameter, are shown to be related to this elastic coupling of the MnF 4− 6 complex to the rest of the host lattice. The present results support the conclusion that the Stokes shift is determined by the interaction of the excited 4 T 1g state with a 1g and e g local modes while the coupling with the t 2g shear mode is not relevant. The variations of local vibrational frequencies and the Stokes shift induced by a hydrostatic pressure on a given system are shown to be rather different to those produced by the chemical pressure associated with distinct host lattices.

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Section: Coupling Constants For Thementioning

confidence: 99%

Section: Coupling Of 4 T 1g Excited State With Local Modes: Stokes Shiftmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Optical and vibrational properties of MnF₆⁴⁻complexes in cubic fluoroperovskites: insight through embedding calculations using Kohn–Sham equations with constrained electron density

Garcı́a-Lastra

Wesołowski

Barriuso

et al. 2006

J. Phys.: Condens. Matter

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“…This spin crossover transition produces a strong variation in the emission pattern going from a broad band to a sharp one. [7][8][9][10] Among the host lattices used for incorporating Cr 3+ impurities, a great deal of work has been carried out on those involving a trivalent cation [10][11][12][13][14][15][16][17][18][19] such as Al 2 O 3 , K 2 NaScF 6 , K 2 NaYCl 6 , or LiCaAlF 6 . Indeed in these cases, the Cr 3+ impurity enters the trivalent site thus giving rise to a center without any close charge compensation, a situation which is thus markedly different from that appearing in systems such as KMF 3 :Cr 3+ or K 2 MF 4 :Cr 3+ ͑M = Mg and Zn͒ where different centers are simultaneously observed.…”

mentioning

confidence: 99%

Pressure-induced changes inCr3+-doped elpasolites andLiCaAlF6: Interpretation of macroscopic data

et al. 2010

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Applications of the group-function theory to the field of materials science

Seijo

Barandiarán

1996

Int. J. Quantum Chem.

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The group-function theory, as proposed by McWeeny for the study of weak intermolecular interactions and developed by Huzinaga in the context of valence-electron methods, is shown to be applicable to the ab initio study of tunable solid-state laser materials made of defective ionic crystals. The applicability of the theory relies on the existence of local electronic states (to which the demonstrated/potential laser activity is ascribed), which are essentially localized in a small cluster of atoms including the defect and whose electron correlation interactions with the surrounding crystal components are negligible. According to the group-function formalism, it is possible (a) to neglect electron correlation effects beyond the defect cluster and (b) to define a quantum mechanical embedding potential which embodies the rest of the so-called host effects. Computationally, the theory becomes applicable as the embedding potential is approximated through ab initio model potentials (AIMP). The results of AIMP embedded-cluster calculations demonstrate that it is possible to calculate the local structure and spectroscopy of the active defect at an ab initio level, the attainable accuracy being comparable to the usual one in molecular ab initio studies in the gas phase. Also, in this article, we present a systematic study of the local distortions produced upon doping divalent first-series transition-metal ions in rock-salt oxides, MOMe2+ (M=Mg, Ca, Sr; Me=Sc-Zn) and TIt in KMgF, and KF hosts. This study leads to the calculation of the local structures of the defects in these materials, which have not been measured. The results suggest that the use of the mismatch of the empirical ionic radii of the impurity and the substituted ion in order to pre$ct local distortions in doped ionic crystals is not significant when it is smaller than 0.1 A, and when it is larger, it should be weighted by a reduction factor depending on the host. For the first-series divalent transition-metal ion impurities, this factor is shown to be 0.15 for SrO, 0.25 for CaO, and around 0.50 for MgO.

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Pressure and temperature dependence of chromium photoluminescence spectra in fluoride elpasolites

Cited by 61 publications

References 12 publications

Optical and vibrational properties of MnF₆⁴⁻complexes in cubic fluoroperovskites: insight through embedding calculations using Kohn–Sham equations with constrained electron density

Optical and vibrational properties of MnF₆⁴⁻complexes in cubic fluoroperovskites: insight through embedding calculations using Kohn–Sham equations with constrained electron density

Pressure-induced changes inCr3+-doped elpasolites andLiCaAlF6: Interpretation of macroscopic data

Applications of the group-function theory to the field of materials science

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Pressure and temperature dependence of chromium photoluminescence spectra in fluoride elpasolites

Cited by 61 publications

References 12 publications

Optical and vibrational properties of MnF64−complexes in cubic fluoroperovskites: insight through embedding calculations using Kohn–Sham equations with constrained electron density

Optical and vibrational properties of MnF64−complexes in cubic fluoroperovskites: insight through embedding calculations using Kohn–Sham equations with constrained electron density

Pressure-induced changes inCr3+-doped elpasolites andLiCaAlF6: Interpretation of macroscopic data

Applications of the group-function theory to the field of materials science

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Optical and vibrational properties of MnF₆⁴⁻complexes in cubic fluoroperovskites: insight through embedding calculations using Kohn–Sham equations with constrained electron density

Optical and vibrational properties of MnF₆⁴⁻complexes in cubic fluoroperovskites: insight through embedding calculations using Kohn–Sham equations with constrained electron density