Third-order correlation theory of electronic Raman scattering for rare-earth ions in crystals. II. Numerical analysis for ions across the lanthanide series

1989 ◽  
Vol 40 (10) ◽  
pp. 6499-6504 ◽  
Author(s):  
Lidia Smentek-Mielczarek
Keyword(s):  
Rare Earth ◽  
Numerical Analysis ◽  
Raman Scattering ◽  
Rare Earth Ions ◽  
Third Order ◽  
Correlation Theory ◽  
Lanthanide Series ◽  
Electronic Raman Scattering

Electronic Raman Spectra. VII. Raman Spectra of the Lanthanides

1971 ◽  
Vol 49 (13) ◽  
pp. 2336-2344 ◽  
Author(s):  
J. A. Koningstein ◽  
P. Grunberg
Keyword(s):  
Experimental Data ◽  
Rare Earth ◽  
Raman Scattering ◽  
Raman Spectra ◽  
Rare Earth Ions ◽  
Lanthanide Ions ◽  
Electronic Transitions ◽  
Raman Transition ◽  
Trivalent Lanthanides ◽  
Electronic Raman Scattering

Additional experimental data are reported on electronic Raman scattering of trivalent lanthanides, making the observation of this effect of the series nearly complete. The bulk of the information now available points to the fact that the intensity of electronic Raman transition is strongest for the rare earth ions in the middle of the series. The most profound differences of polarization features of electronic transitions and phonons is observed in the situation where the lanthanide ions have an odd number of 4f electrons. Antisymmetric scattering tensors play a less important role.

Magnetic Linear Birefringence in Rare Earth Systems. II. Third-Order Approach

2004 ◽  
Vol 69 (1) ◽  
pp. 34-46
Author(s):  
Lidia Smentek
Keyword(s):  
Rare Earth ◽  
Field Potential ◽  
Second Order ◽  
Rare Earth Ions ◽  
Lanthanide Ions ◽  
Linear Birefringence ◽  
Third Order ◽  
The Third ◽  
The Impact ◽  
Effective Operators

The theory of linear magnetic birefringence of rare earth ions in crystals is extended here by the contributions that represent a direct perturbing influence of the crystal field potential surrounding the central ion. The basic assumptions of the theoretical model are the same as in the previous analysis of second-order terms. The third-order contributions introduced here break the free ionic system approximation, and they represent the impact due to configuration interaction. The effective operators include the perturbing influence of the excitations from the 4f shell to one-electron states of the same parity (as previously at the second order), and in addition, the excitations to states of opposite parity. All contributing terms are expressed by the effective operators that are defined within the perturbed function approach. The tensorial structure of these operators is discussed, and special attention is directed to newly defined radial integrals. The values of all radial integrals that are necessary for the third-order numerical analysis are presented in the case of all lanthanide ions.

Characterization of Rare-Earth Fluoride Anti-Stokes Phosphors by Scanning arid Transmission Electron Microscopy

1971 ◽  
Vol 29 ◽  
pp. 142-143
Author(s):  
N. M. P. Low ◽  
L. E. Brosselard
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Elevated Temperatures ◽  
Stoichiometric Composition ◽  
Rare Earth Ions ◽  
Crystalline Solid ◽  
Precipitation Process ◽  
Rare Earth Fluoride ◽  
Earth Fluoride ◽  
Rare Earth Fluorides

There has been considerable interest over the past several years in materials capable of converting infrared radiation to visible light by means of sequential excitation in two or more steps. Several rare-earth trifluorides (LaF3, YF3, GdF3, and LuF3) containing a small amount of other trivalent rare-earth ions (Yb3+ and Er3+, or Ho3+, or Tm3+) have been found to exhibit such phenomenon. The methods of preparation of these rare-earth fluorides in the crystalline solid form generally involve a co-precipitation process and a subsequent solid state reaction at elevated temperatures. This investigation was undertaken to examine the morphological features of both the precipitated and the thermally treated fluoride powders by both transmission and scanning electron microscopy.Rare-earth oxides of stoichiometric composition were dissolved in nitric acid and the mixed rare-earth fluoride was then coprecipitated out as fine granules by the addition of excess hydrofluoric acid. The precipitated rare-earth fluorides were washed with water, separated from the aqueous solution, and oven-dried.

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