Nephelauxetic effect and 〈r〉4f radial integrals of Pr3+ in crystals

Angelov, B.

doi:10.1016/j.jallcom.2004.05.074

Cited by 3 publications

(1 citation statement)

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“…Correction terms to the Slater parameters for d-electron systems were given by Morrison et al 17 and for f-electron systems by Newman. 14 Assuming the validity of this dielectric screening model, Angelov 18 utilized the Slater parameter shifts from the free ion values together with the dielectric permittivity of crystals doped with, or containing Pr 3+ , to calculate the radial integrals ⟨r k ⟩ (k = 2, 4, 6) for Pr 3+ in certain solid-state materials. The values for ⟨r 4 ⟩ and ⟨r 6 ⟩ each varied by more than a factor of 2 for the different crystals.…”

Section: ■ Introductionmentioning

confidence: 99%

Nephelauxetic Effects in the Electronic Spectra of Pr³⁺

Tanner

Yeung

2013

J. Phys. Chem. A

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The well-known nephelauxetic series of ligands describes the change in interelectronic repulsion of the central metal ion, which is reduced on going from the vapor to crystalline state. This study examines the trends and quantifies the mechanism of this series for the lanthanide ion Pr(3+), with the 4f(2) electronic configuration. A new and concise measurement by a single parameter, σee, is introduced to quantify the overall strength of interelectronic repulsion, as the alternative to the Slater parameters, F(k) (k = 2, 4, 6). Energy parameters have been derived from the literature electronic spectra of Pr(3+), in the free ion and in various crystalline hosts, with new calculations in some cases. It is found that at least the first 12 of the 13 multiplet terms of Pr(3+) must be well-determined to obtain reliable parameter values. The shifts of various energy levels for changes in the Slater parameters are not uniform in direction. For the various Pr(3+) solid-state systems, the change in σee is only up to ∼5%, with the magnitude of σee in the order F(-) > Cl(-) > O(2-) ≈ Br(-) > C, and decreasing with lower coordination number of the ligand. The decreases of the Slater parameters from the free ion values are reasonably estimated by considering the dielectric constant of the medium. In particular, the magnitude of σee (and of the spin-orbit coupling constant) is proportional to the polarizability of the ligand for F(-), Cl(-), O(2-), and Br(-). The data point scatter for oxide systems is accounted for by considering the individual ligand bond distances. A fair estimation of nephelauxetic effects can be made from some luminescence transition energies, by contrast with Eu(3+) systems where crystal field effects also play a major role. In conclusion, the nephelauxetic effect of Pr(3+) is due to the polarization of the ligand by one 4f electron, and the interaction of the other electron with the induced multipolar moments, of which the dipole moment dominates.

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Section: ■ Introductionmentioning

confidence: 99%