Extended analysis of the Eu  III spectrum

Wyart, J.-F.; Tchang-Brillet, W. Ü. L.; Churilov, S S; Ryabtsev, A. N.

doi:10.1051/0004-6361:20079333

Cited by 22 publications

(13 citation statements)

References 23 publications

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“…Figure 8 shows experimental data on the spin-orbit coupling parameters ζ ff for the free lanthanides. Ce 2+ is from [24], Pr 3+ , Nd 3+ , and Nd 4+ from [27], Eu 2+ from [25], Er 2+ from [26], Er 3+ from [28], Tm 3+ from [29], and Yb 4+ from [30]. The solid curves connect the calculated results from [13] that are listed in Table III.…”

Section: Theorymentioning

confidence: 68%

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The nephelauxetic effect on the electron binding energy in the 4f ground state of lanthanides in compounds

Dorenbos

2019

Journal of Luminescence

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In the construction of a vacuum referred binding energy (VRBE) diagram with the lanthanide 4f q ground states, always a compound independent variation with the number q = 1 to 14 is assumed. Experimental data from thermo-luminescence, intervalence charge transfer bands, and thermo-bleaching studies provide first indications that a minor compound dependence does exist.To explain its origin we will first apply the Jørgensen spin pairing theory to reproduce the VRBE in the ground states of the free di-and trivalent lanthanide ions which is equivalent to the 3 rd and 4 th ionization potentials of the lanthanide atoms. By combining experimental data and calculated trends therein, the relevant Racah E 1 , Racah E 3 , and spin orbit coupling ζ ff parameters for all di-, tri-, and tetravalent free ion lanthanides are derived. Using that as input for the spin pairing theory, the characteristic zigzag shapes in VRBE as function of q, as derived from ionization potentials, are nicely reproduced. Because of the nephelauxetic effect the parameter values are lowered when lanthanides are in compounds. How that reduction affects the VRBE curves will be treated in this work.

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Section: Theorymentioning

confidence: 68%

“…Data are from [13] and in eV. from [24][25][26], the trivalent lanthanides Pr, Nd, Er, Tm from [14,[27][28][29], and the tetravalent Nd, and Yb from [27,30]. The dashed lines are the calculated linear relationships from Table III corrected with a constant value chosen such that the lines run through the experimental data points.…”

Section: Theorymentioning

confidence: 99%

The nephelauxetic effect on the electron binding energy in the 4f ground state of lanthanides in compounds

Dorenbos

2019

Journal of Luminescence

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“…These data were supplemented by the transition probabilities for the observed and predicted lines of Pr ii−Pr iii ), Nd ii−Nd iii (Mashonkina et al 2005;Ryabchikova et al 2006), Eu iii (Wyart et al 2008), Tb iii and Dy iii (Ryabtsev, private communication), hereafter referred to as "ISAN data". For the latter two ions transition probability calculations were based on the extended term analysis.…”

Section: Ree Line Lists For Model Atmosphere Calculationmentioning

confidence: 99%

“…The main sources for the REEs transition probabilities data between experimentally known energy levels are VALD and DREAM databases, hereafter referred to "VALD data". These data were supplemented by the transition probabilities for the observed and predicted lines of Pr ii-Pr iii (Mashonkina et al 2009), Nd ii-Nd iii (Mashonkina et al 2005;Ryabchikova et al 2006), Eu iii (Wyart et al 2008), Tb iii and Dy iii (Ryabtsev, private communication), hereafter referred to as "ISAN data". For the latter two ions transition probability calculations were based on the extended term analysis.…”

Section: Ree Line Lists For Model Atmosphere Calculationmentioning

confidence: 99%

Realistic model atmosphere and revised abundances of the coolest Ap star HD 101065

Shulyak

Ryabchikova

Kildiyarova

et al. 2010

A&A

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Aims. Among the known Ap stars, HD 101065 is probably one of the most interesting objects, demonstrating very rich spectra of rareearth elements (REE). Strongly peculiar photometric parameters of this star can not be fully reproduced by any modern theoretical calculations, even those accounting for realistic chemistry of its atmosphere. In this study we investigate a role of missing REE line opacity and construct a self-consistent atmospheric model based on accurate abundance and chemical stratification analysis. Methods. We employed the LLmodels stellar model atmosphere code together with DDAFit and Synthmag software packages to derive homogeneous and stratified abundances for 52 chemical elements and to construct a self-consistent model of HD 101065 atmosphere. The opacity in REE lines is accounted for in details, by using up-to-date extensive theoretical calculations. Results. We show that REE elements play a key role in the radiative energy balance in the atmosphere of HD 101065, leading to the strong suppression of the Balmer jump and energy redistribution very different from that of normal stars. Introducing new line lists of REEs allowed us to reproduce, for the first time, spectral energy distribution of HD 101065 and achieve a better agreement between the unusually small observed Strömgren c 1 index and the model predictions. Using combined photometric and spectroscopic approaches and based on the iterative procedure of abundance and stratification analysis we find effective temperature of HD 101065 to be T eff = 6400 K.

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“…In theoretical calculations, by means of the Cowan-code package [15,16], the adopted set of 4f 10 , 4f 9 6p and 4f 9 5d, 4f 9 6s configurations represented a total of 3549 possible energy levels. The same approach was used for calculations in doubly ionized europium [17,18]. The configurations considered in the calculations were 4f 7 , 4f 6 6p for the odd parity and 4f 6 5d, 4f 6 6s for the even parity.…”

Section: Introductionmentioning

confidence: 99%