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.

Characterization of Aluminophosphate Glasses Containing Pr3+, Er3+, Gd3+ and Yb3+ Ions

2008 ◽  
Vol 39-40 ◽  
pp. 61-64 ◽  
Author(s):  
M. Elisa ◽  
Ileana Cristina Vasiliu ◽  
Cristiana Eugenia Ana Grigorescu ◽  
B. Grigoras ◽  
H. Niciu ◽  
...  
Keyword(s):  
Rare Earth ◽  
Absorption Spectra ◽  
Glass Network ◽  
Phosphate Glasses ◽  
Rare Earth Ions ◽  
Electronic Transitions ◽  
Ir Absorption ◽  
Optical Phonons ◽  
Infra Red ◽  
Aluminophosphate Glasses

A wet non-conventional method for preparing aluminophosphate glasses is presented. Aluminophosphate glasses belonging to the oxide system Li2O-BaO-Al2O3-La2O3-P2O5, doped with rare-earth ions (Pr3+, Er3+, Gd3+, and Yb3+) were obtained. The influence of the doping ions on the optical properties of the phosphate glasses has been investigated in relation with micro-structural and local electronic phenomena The optical behavior of Li2O-BaO-Al2O3-La2O3-P2O5 glasses doped with 3% mol. rare-earth ions has been studied by ultra-violet-visible-near-infra-red (UV-VISNIR) spectroscopy. The transmission spectra revealed electronic transitions between 4f and 6s inner orbital of the rare-earth ions. Structural information via optical phonons was provided by infra-red (IR) absorption spectra in the range 400-4000 cm-1. IR optical phonons are characteristic for the vitreous phosphate network, showing out the glass network-forming role of P2O5. The absorption spectra present the main PO2 and P-O-P symmetrical stretch modes besides P-O-P bend mode, P-OH, P=O, PO3 2-, asymmetrical and symmetrical vibration modes. Fluorescence spectra of the rareearth- doped aluminophosphate glasses, in the visible range, were obtained by laser excitation at 514.5 nm. The fluorescence signals revealed specific electronic transitions, which provide visible and near-infra-red emission. Glasses containing rare-earth ions exhibit luminescence at the following wavelengths: Pr3+ ions at 820 nm and 880 nm, Er3+ ions at 520 nm, 550 nm and 560 nm, Gd3+ ions at 530 nm, 540 nm, 550 nm 820 and 880 nm, Yb3+ions at 530 nm, 540 nm, 550 nm and 980 nm.

Raman scattering and theoretical studies of Jahn—Teller induced phase transitions in some rare-earth compounds

1972 ◽  
Vol 328 (1573) ◽  
pp. 217-266 ◽  
Keyword(s):  
Rare Earth ◽  
Phase Transitions ◽  
Raman Scattering ◽  
Raman Spectra ◽  
Mode Coupling ◽  
Equations Of Motion ◽  
Structural Phase ◽  
Phase Changes ◽  
Phonon Modes ◽  
Jahn Teller

The rare-earth crystals DyVO 4 , DyAsO 4 and TbVO 4 undergo structural phase transitions at 14, 12 and 34 K respectively induced by a cooperative Jahn-Teller effect. An experimental investigation of the phase changes has been made using Raman scattering methods. For purposes of comparison, the Raman spectra of DyPO 4 , YVO 4 and GdVO 4 (which do not undergo phase transitions) have also been measured. A detailed theory of the phase transitions has been developed which accounts for the electronic and vibrational Raman spectra. The lowest four electronic levels of Dy 3+ and Tb 3+ are treated in a pseudospin formalism, and the theory is discussed in terms of mixed phonon and pseudo-spin excitations. The singly degenerate κ ≈ 0 optic phonons are not measurably affected by the transitions, but splittings of up to 20 cm -1 developed in the doubly degenerate E g phonon modes in the Raman spectra owing to anharmonic couplings with the electronic states. Splittings are also observed in the lowest electronic levels of the rate earth ions below the transition temperature; these electronic modes effectively constitute the soft mode which causes the transitions to occur. A molecular field model is first used in the theoretical analysis. The equations of motion of the coupled excitations are then found and the energies, line widths and dispersion of the mixed excitations are discussed. The connexion between the static strain and the acoustic phonon mode coupling is investigated, and a thermodynamic treatment of the elastic constants is given. From the Raman data, it appears that in TbVO 4 the acoustic mode coupling is stronger than the optic mode coupling.

scholarly journals Raman Scattering in Cuprate Superconductors

1997 ◽  
Vol 11 (18) ◽  
pp. 2093-2118 ◽  
Author(s):  
Thomas Peter Devereaux ◽  
Arno Paul Kampf
Keyword(s):  
Low Temperature ◽  
Raman Scattering ◽  
Raman Spectra ◽  
Cuprate Superconductors ◽  
Energy Gap ◽  
Low Frequency ◽  
Temperature Behavior ◽  
Doping Dependence ◽  
Electronic Raman Scattering ◽  
Effects Of Disorder

A theory for electronic Raman scattering in the cuprate superconductors is presented with a specific emphasis on the polarization dependence of the spectra which can infer the symmetry of the energy gap. Signatures of the effects of disorder on the low frequency and low temperature behavior of the Raman spectra for different symmetry channels provide detailed information about the magnitude and the phase of the energy gap. Properties of the theory for finite T will be discussed and compared to recent data concerning the doping dependence of the Raman spectra in cuprate superconductors, and remaining questions will be addressed.

Electronic Transitions of Rare Earth Ions in the Infrared Region

1960 ◽  
Vol 33 (1) ◽  
pp. 192-193 ◽  
Author(s):  
G. Mandel ◽  
R. P. Bauman ◽  
E. Banks
Keyword(s):  
Rare Earth ◽  
Infrared Region ◽  
Rare Earth Ions ◽  
Electronic Transitions

Temperature dependent Raman scattering and electronic transitions in rare earth SmFeO3

2018 ◽  
Vol 44 (4) ◽  
pp. 4198-4203 ◽  
Author(s):  
Surbhi Gupta ◽  
Rohit Medwal ◽  
Shojan P. Pavunny ◽  
Dilsom Sanchez ◽  
Ram S. Katiyar
Keyword(s):  
Rare Earth ◽  
Raman Scattering ◽  
Electronic Transitions ◽  
Temperature Dependent
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