Prediction on Mn4+ -Doped Germanate Red Phosphor by Crystal Field Calculation on Basis of Exchange Charge Model: A Case Study on K2 Ge4 O9 :Mn4+

2016 ◽  
Vol 99 (7) ◽  
pp. 2388-2394 ◽  
Author(s):  
Pengfei Li ◽  
Mikhail G. Brik ◽  
Lejing Li ◽  
Jin Han ◽  
Xiaoman Li ◽  
...  
2019 ◽  
Vol 21 (4) ◽  
Author(s):  
M.G. Brik ◽  
◽  
N.M. Avram ◽  
C.N. Avram ◽  
◽  
...  

Open Physics ◽  
2005 ◽  
Vol 3 (4) ◽  
Author(s):  
Mikhail Brik ◽  
Nicolae Avram ◽  
Calin Avram

AbstractThe exchange charge model of crystal field theory has been used to analyze the ground and excited state absorption of tetrahedrally coordinated Cr4+ ion in lithium aluminum oxide LiAlO2 (γ-phase) and lithium dioxogallate LiGaO2. The parameters of the crystal field acting on the Cr4+ ion are calculated from the crystal structure data, taking into account the crystal lattice ions located at distances up to 12.744 Å in LiGaO2 and 13. 180 Å in LiAlO2. The obtained energy level schemes were compared with experimental ground and excited state absorption spectra and literature data on the application of other crystal field models (the angular overlap model and Racah theory) to the considered crystals; a good agreement with experimental data is demonstrated.


2006 ◽  
Vol 20 (17) ◽  
pp. 1007-1014 ◽  
Author(s):  
M. G. BRIK

Optical absorption spectrum of Cr4+ion in Rb2CrF6is analyzed using the exchange charge model of crystal field theory. The crystal field parameters acting on the optical electrons of Cr4+are calculated using the crystal structure data; a good agreement between the calculated and observed energy levels of Cr4+in the title host is demonstrated. The crystal field strength Dq=2159 cm-1and Racah parameters B=639 cm-1, C=3605 cm-1were evaluated from the experimental spectrum.


1977 ◽  
Vol 55 (10) ◽  
pp. 937-942 ◽  
Author(s):  
A. F. Leung ◽  
Ying-Ming Poon

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.


2003 ◽  
Vol 353 (1-2) ◽  
pp. 95-101 ◽  
Author(s):  
Min Yin ◽  
Yunfeng Li ◽  
Ning Dong ◽  
V.N. Makhov ◽  
N.M. Khaidukov ◽  
...  

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