Defect model and spin-Hamiltonian parameters for the tetragonal Nd3+ center in the tetragonal phase of SrTiO3 crystal

2011 ◽  
Vol 406 (4) ◽  
pp. 1041-1043 ◽  
Author(s):  
Wei-Qing Yang ◽  
Wen-Chen Zheng ◽  
Ping Su ◽  
Hong-Gang Liu
2014 ◽  
Vol 69 (10-11) ◽  
pp. 606-610 ◽  
Author(s):  
Wei-Qing Yang ◽  
Wen-Chen Zheng

AbstractThe spin-Hamiltonian parameters (g factors g||, g⊥, and zero-field splittings b02 , b04 , b44 , b06 , b46 ) of the 4f7 Gd3+ ion in the tetragonal phase of a BaTiO3 crystal are calculated through the diagonalization (of energy matrix) method based on the one-electron crystal field mechanism. In the calculations, the crystal field parameters are estimated from the superposition model with the structural data of the studied crystal. It is found that by using three adjustable intrinsic parameters Āk(R0) (k=2, 4, 6) in the superposition model, the seven calculated spin-Hamiltonian parameters are in good agreement with the experimental values, suggesting that the diagonalization method based on one-electron crystal field mechanism is effective in the studies of spin-Hamiltonian parameters for 4f7 ions in crystals.


2007 ◽  
Vol 21 (04) ◽  
pp. 225-236 ◽  
Author(s):  
P. LIMSUWAN ◽  
N. UDOMKAN ◽  
P. WINOTAI

In this report, Fe 3+ impurity ions present in green sapphire ( Al 2 O 3) were studied experimentally, by heating a light green sapphire in flowing oxygen atmosphere for 12 h from 1200, 1300, 1400, 1500 and 1600°C, respectively. Electron spin resonance (ESR) spectra in X-band (~9.45 GHz ) were recorded by mounting the crystal with the c-axis perpendicular (θ = 90°) to the magnetic field direction. The spectra were recorded and simulated by a numerical diagonalization of spin Hamiltonian matrix in the range from 0 to 180 degrees for every 15 degrees of rotation angle (φ). In our case, only the last two sets of peaks strongly depend on the rotation angle (φ), and each exhibits C 3 symmetry due to two magnetically inequivalent Fe 3+ sites in the corundum structure. For polycrystalline ESR spectra, seven main Fe 3+ ESR absorption peaks occur at the resonance magnetic fields of 100.20, 310.24, 486.80, 525.00, 550.60, 761.00 and 777.00 mT respectively. Specifically, ESR signals show that the number of paramagnetic Fe 3+ ions increase roughly linearly with the heat treating temperature, having the [Formula: see text] ratio ~1.41 at 1600°C.


Author(s):  
Yujeong Kim ◽  
Jin Kim ◽  
Linh. K. Nguyen ◽  
Yong-Min Lee ◽  
Wonwoo Nam ◽  
...  

Multifrequency, multitechnique pulse EPR spectroscopy was employed to unravel the spin Hamiltonian parameters of 17O in the [FeV=O] moiety with two different tetraamido macrocyclic ligands (TAMLs), [FeV(O)(TAML-1)]– (1, H4(TAML-1) =...


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