A Theoretical Study on the Spin-Hamiltonian Parameters for Samarium(III) Ion in Potassium Yttrium Tungstate Crystal

2011 ◽  
Vol 66 (3-4) ◽  
pp. 139-142 ◽  
Author(s):  
Wei-Qing Yang ◽  
Wen-Chen Zheng ◽  
Ping Su ◽  
Hong-Gang Liu

The nine spin-Hamiltonian (SH) parameters (g-factors gi and hyperfine structure constants 147Ai and 149Ai for 147Sm3+ and 149Sm3+ isotopes, where i = x, y, z) for the Samarium(III) ion in monoclinic potassium yttrium tungstate [KY(WO4)2] crystal are calculated within the rhombic symmetry approximation from a diagonalization of energy matrix method. Differing from the conventional diagonalization method used in the calculation of crystal-field levels, in the present method, we attach the Zeeman (or magnetic) and hyperfine interaction terms to the conventional Hamiltonian and construct the 66×66 energy matrix for 4f5 ions in rhombic crystal field and under an external magnetic field by considering all the ground-term multiplets 4HJ. The calculated results are in reasonable agreement with the experimental values

2009 ◽  
Vol 23 (20n21) ◽  
pp. 2457-2462 ◽  
Author(s):  
HONG-GANG LIU ◽  
WEN-CHEN ZHENG ◽  
WEN-LIN FENG ◽  
WEI-QING YANG

The spin-Hamiltonian parameters (g factors gi and hyperfine structure constants Ai, where i = x, y, z) and optical spectrum band positions of the Yb 3+ ion in the rhombically-distorted Tm 3+ site of Tm 3 Al 5 O 12 garnet crystal are calculated by a complete diagonalization (of the energy matrix) method, in which the Zeeman and hyperfine interaction terms are also included in the conventional Hamiltonian. From the calculations, the observed spin-Hamiltonian parameters of Tm 3 Al 5 O 12: Yb 3+ are explained reasonably and the optical spectrum band positions are suggested. The rationality of these suggested optical spectrum band positions is discussed by comparing them with the observed values of Yb 3+ ions in similar aluminum garnet ( Yb 3 Al 5 O 12, Y 3 Al 5 O 12 and Lu 3 Al 5 O 12) crystals.


2010 ◽  
Vol 24 (03) ◽  
pp. 289-296 ◽  
Author(s):  
HUI-NING DONG ◽  
DENG-FENG LI ◽  
JUN LIU ◽  
DAVID J. KEEBLE

The electronic paramagnetic resonance g factors g‖, g⊥of Dy3+centers and the hyperfine structure constants A‖and A⊥of161Dy3+and163Dy3+isotopes in ZrSiO4crystal are theoretically studied from the perturbation formulas of the spin Hamiltonian parameters for a 4f9ion in tetragonal symmetry. In these formulas, the contributions to g factors due to the J-mixing among the ground6H15/2, the first excited6H13/2and second excited6H11/2states via crystal-field interaction, the admixtures among the states with the same J value via spin-orbit coupling interaction and the interactions between the lowest Kramers doublet Γγ and other 20 Kramers doublets ΓXwithin the states6HJ(J=15/2, 13/2 and 11/2) via crystal-field and orbital angular momentum interactions are considered. The calculated EPR parameters show reasonable agreement with the observed values. The results are discussed.


2008 ◽  
Vol 22 (07) ◽  
pp. 843-850 ◽  
Author(s):  
SHAO-YI WU ◽  
XIU-YING GAO ◽  
JI-ZI LIN ◽  
QIANG FU ◽  
HUA-MING ZHANG

The spin Hamiltonian (SH) parameters g factors g‖, g⊥and the hyperfine structure constants A‖and A⊥for the tetragonal Cu2+centers (i.e., [ CuX4( H2O )2] clusters) in NH4X ( X = Cl, Br, I ) are theoretically investigated by means of the diagonalization procedure of complete (10×10) energy matrix (DPCEM) for a 3d9ion in tetragonal symmetry. The crystal-field parameters in the energy matrix are determined from the superposition model. The calculated SH parameters are in reasonable agreement with the experimental data.


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.


2010 ◽  
Vol 88 (5) ◽  
pp. 301-306 ◽  
Author(s):  
Xue-Feng Wang ◽  
Shao-Yi Wu ◽  
Li-Li Li ◽  
Shan-Xiang Zhang

The spin Hamiltonian parameters (g factors and the hyperfine structure constants) for the cubic Mn2+ centers in ZnX (X = S, Se, Te) and CdTe are investigated theoretically using the perturbation formulas of these parameters for a tetrahedral 3d5 cluster containing both the crystal-field and charge-transfer contributions. The relevant molecular orbital coefficients are uniformly determined from the cluster approach, and the calculated spin Hamiltonian parameters are in good agreement with the observed values. The g-shifts of the g factors related to the pure spin value gs (≈ 2.0023) arising from the charge transfer contributions are opposite (positive) in sign and much larger in magnitude than those from the crystal field contributions. On the other hand, the contributions from the charge-transfer mechanism to the hyperfine structure constants are the same in sign and about 20%–30% in magnitude of those from the crystal-field mechanism. The importance of the charge transfer contributions increases significantly with the increase of the covalency and the spin–orbit coupling coefficient of the ligand, i.e., S2− < Se2− < Te2−.


2006 ◽  
Vol 61 (12) ◽  
pp. 688-690 ◽  
Author(s):  
Gui-Qiang Qu ◽  
Wang Fang ◽  
Wen-Chen Zhenga

The spin Hamiltonian parameters (g factors g||, g⊥ and hyperfine structure constants A||, A⊥) of Zr3+ on the tetragonal M3+ (M = Sc, Lu, Y) sites of zircon-type orthophosphate MPO4 crystals are calculated by high-order perturbation formulas of d1 ions in tetragonal symmetry. The crystal-field parameters are estimated by the superposition model and reasonable local structural data of impurity centers. The results show good agreement with the experimental values. It appears that in the case of size mismatch, the explanation of the spin Hamiltonian parameters of a paramagnetic impurity in crystals should take the impurity-induced local lattice relaxation into account.


2005 ◽  
Vol 60 (3) ◽  
pp. 145-148 ◽  
Author(s):  
Xiu-Ying Gao ◽  
Shao-Yi Wu ◽  
Wang-He Wei ◽  
Wei-Zi Yan

The spin Hamiltonian g factors and the hyperfine structure constants for V2+ in CsMgX3 (X = Cl, Br, I) are theoretically studied by using the perturbation formulas of these parameters for a 3d3 ion in octahedral symmetry, based on the cluster approach. In such formulas, the contributions from the s-orbitals of the ligands were usually neglected. Here they are taken into account. The theoretical results (particularly the g factor for CsMgI3) show a significant improvement compared with those in absence of the ligand s-orbital contributions in the previous studies.


2004 ◽  
Vol 59 (12) ◽  
pp. 943-946 ◽  
Author(s):  
Hui-Ning Dong ◽  
Shao-Yi Wu

In this paper, the spin Hamiltonian parameters g factors g∥ and g⊥ of Yb3+ and hyperfine structure constants A∥ and A⊥ of 171Yb3+ and 173Yb3+ in CaWO4 crystal are calculated from the two-order perturbation formulae. In these formulae, the contributions of the covalence effects, the admixture between J =7/2 and J =5/2 states as well as the second-order perturbation are included. The needed crystal parameters are obtained from the superposition model and the local structure of the studied system. The calculated results are in reasonable agreement with the observed values. The results are discussed.


2004 ◽  
Vol 59 (7-8) ◽  
pp. 471-475
Author(s):  
Shao-Yi Wu ◽  
Hui-Ning Dong

In this work, the spin Hamiltonian (SH) parameters g|| and g⊥, and the hyperfine structure constants A|| and A⊥ for ZrSiO4:Np4+ are investigated on the basis of the perturbation formulas of these parameters for a 5f3 ion in tetragonal (D2d) symmetry. In these formulas, the contributions to the SH parameters from the second-order perturbation terms, the admixtures of various energy levels and the covalency effect are taken into account. The related crystal-field parameters are calculated from the superposition model and the local structural data of the Zr4+ site occupied by the impurity Np4+. The calculated SH parameters agree reasonably with the experimental data. The validity of the theoretical results is discussed.


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