Electronic transitions and genuine crystal-field parameters in copper metaborate CuB2O4

2011 ◽  
Vol 84 (7) ◽  
Author(s):  
R. V. Pisarev ◽  
A. M. Kalashnikova ◽  
O. Schöps ◽  
L. N. Bezmaternykh
Keyword(s):  
Crystal Field ◽  
Electronic Transitions ◽  
Crystal Field Parameters

Das Temperaturverhalten der Phosphoreszenz und Fluoreszenz von K3CrF6 / The Temperature Dependence of Phosphorescence and Fluorescence in K3CrF6

1973 ◽  
Vol 28 (7) ◽  
pp. 1131-1135
Author(s):  
E. Koglin
Keyword(s):  
Experimental Data ◽  
Temperature Dependence ◽  
Crystal Field ◽  
Fluorescence Emission ◽  
Electronic Transitions ◽  
Luminescence Spectra ◽  
Site Symmetry ◽  
Energy Eigenvalues ◽  
Crystal Field Parameters ◽  
Fluorescence And Phosphorescence

The luminescence behaviour of crystalline K3CrF6 is measured in the temperature range from 100 °K to 4.2 °K. The complex shows a very strong, broad fluorescence emission at temperatures lower than 20 °K. additionally also the phosphorescence transition can be observed. At temperatures higher than 20 °K only fluorescence is measured. The 2E→4A2-transition does not split suggesting Oh-site symmetry.Excitation- and luminescence spectra at 4.2 °K are the basis for a calculation of the energy eigenvalues. The crystal field parameters are fitted by the experimental data. The vibrational sidebands of the electronic transitions 2E - 4A2 an 4T24A2 are compared with Raman- and IRresults. From the temperature dependence and measured vibrational frequencies the zero phonon transitions of fluorescence and phosphorescence can be found

An Intuitive Method for the Determination of Crystal-Field Parameters in Laser Crystals

1993 ◽  
Vol 329 ◽  
Author(s):  
Frederick G. Anderson ◽  
H. Weidner ◽  
P. L. Summers ◽  
R. E. Peale ◽  
B. H. T. Chai
Keyword(s):  
Crystal Field ◽  
Irreducible Representations ◽  
Laser Crystals ◽  
Intuitive Method ◽  
Crystal Field Parameters ◽  
Intuitive Interpretation

AbstractExpanding the crystal field in terms of operators that transform as the irreducible representations of the Td group leads to an intuitive interpretation of the crystal-field parameters. We apply this method to the crystal field experienced by Nd3+ dopants in the laser crystals YLiF4, YVO4, and KLiYF5.

Ground configuration splitting in UCl5

1977 ◽  
Vol 55 (10) ◽  
pp. 937-942 ◽  
Author(s):  
A. F. Leung ◽  
Ying-Ming Poon
Keyword(s):  
Crystal Field ◽  
Energy Levels ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Coupling Constant ◽  
Point Charge Model ◽  
X Ray Crystallography ◽  
Charge Model ◽  
Crystal Field Parameters

The absorption spectra of UCl5 single crystal were observed in the region between 0.6 and 2.4 μm at room, 77, and 4.2 K temperatures. Five pure electronic transitions were assigned at 11 665, 9772, 8950, 6643, and 4300 cm−1. The energy levels associated with these transitions were identified as the splittings of the 5f1 ground configuration under the influence of the spin–orbit coupling and a crystal field of C2v symmetry. The number of crystal field parameters was reduced by assuming the point-charge model where the positions of the ions were determined by X-ray crystallography. Then, the crystal field parameters and the spin–orbit coupling constant were calculated to be [Formula: see text],[Formula: see text], [Formula: see text], and ξ = 1760 cm−1. The vibronic analysis showed that the 90, 200, and 320 cm−1 modes were similar to the T2u(v6), T1u(v4), and T1u(v3) of an UCl6− octahedron, respectively.

Studies of local structures for Cu2+ centers in M2Zn(SO4)2·6H2O (M = NH4 and Rb) crystals

2021 ◽  
Vol 76 (4) ◽  
pp. 299-304
Author(s):  
Fu Chen ◽  
Jian-Rong Yang ◽  
Zi-Fa Zhou
Keyword(s):  
Crystal Field ◽  
Elongation Ratio ◽  
Paramagnetic Resonance ◽  
Local Structures ◽  
Epr Parameters ◽  
Structure Constants ◽  
Crystal Field Parameters ◽  
Electron Paramagnetic ◽  
Theoretical Results ◽  
Good Agreement

Abstract The electron paramagnetic resonance (EPR) parameters (g factor g i , and hyperfine structure constants A i , with i = x, y, z) and local structures for Cu2+ centers in M2Zn(SO4)2·6H2O (M = NH4 and Rb) are theoretically investigated using the high order perturbation formulas of these EPR parameters for a 3d 9 ion under orthorhombically elongated octahedra. In the calculations, contribution to these EPR parameters due to the admixture of d-orbitals in the ground state wave function of the Cu2+ ion are taken into account based on the cluster approach, and the required crystal-field parameters are estimated from the superposition model which enables correlation of the crystal-field parameters and hence the studied EPR parameters with the local structures of the Cu2+ centers. Based on the calculations, the Cu–H2O bonds are found to suffer the axial elongation ratio δ of about 3 and 2.9% along the z-axis, meanwhile, the planar bond lengths may experience variation ratio τ (≈3.8 and 1%) along x- and y-axis for Cu2+ center in (NH4)2Zn(SO4)2·6H2O and Rb2Zn(SO4)2·6H2O, respectively. The theoretical results show good agreement with the observed values.

Pseudocontact shifts in lanthanide complexes with variable crystal field parameters

2011 ◽  
Vol 255 (23-24) ◽  
pp. 2810-2820 ◽  
Author(s):  
Sebastiano Di Pietro ◽  
Samuele Lo Piano ◽  
Lorenzo Di Bari
Keyword(s):  
Crystal Field ◽  
Lanthanide Complexes ◽  
Pseudocontact Shifts ◽  
Crystal Field Parameters

1,3,4-Thiadiazole-2,5-dithiol as a complexing agent. Complexes of RuIII, RuII, RhIII, PdIV IrIII and PtIV

1975 ◽  
Vol 28 (4) ◽  
pp. 763 ◽  
Author(s):  
MR Gajendragad ◽  
U Agarwala
Keyword(s):  
Magnetic Susceptibility ◽  
Metal Ions ◽  
Spectral Data ◽  
Crystal Field ◽  
Complexing Agent ◽  
Chemical Analyses ◽  
Infrared Spectral ◽  
Crystal Field Parameters

Complexes of RuIII, RuII, RhIII, PdIV, IrIII and PtIV with 1,3,4-thiadiazole- 2,5-dithiol have been prepared. Probable structures for the complexes have been proposed on the basis of chemical analyses, magnetic susceptibility and electronic and infrared spectral data. Crystal field parameters have been calculated which are in accordance with the structures proposed. In every complex the ligand behaves as a unidentate towards two metal ions.

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